diff --git a/.rubocop.yml b/.rubocop.yml
index 17ba39d8..7ec9430a 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,16 +1,22 @@
+inherit_from: .rubocop_todo.yml
+
+Layout/SpaceBeforeBlockBraces:
+  Enabled: false
+
+# NOTE: Temporarily duplicated from `rubocop_todo.yml` because many files exceed
+#       120 characters
+# Metrics/LineLength:
+#   Max: 120
+
 Naming/PredicateName:
   NameWhitelist:
     - is_enabled?
 
-Metrics/LineLength:
-  Max: 120
-
-Style/RedundantSelf:
-  Enabled: false
 Style/PreferredHashMethods:
   Enabled: false
-Style/StringLiterals:
+
+Style/RedundantSelf:
   Enabled: false
 
-Layout/SpaceBeforeBlockBraces:
+Style/StringLiterals:
   Enabled: false
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
new file mode 100644
index 00000000..b1a57713
--- /dev/null
+++ b/.rubocop_todo.yml
@@ -0,0 +1,755 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config --exclude-limit 1000`
+# on 2019-09-18 20:34:49 -0500 using RuboCop version 0.74.0.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: TreatCommentsAsGroupSeparators, Include.
+# Include: **/*.gemspec
+Gemspec/OrderedDependencies:
+  Exclude:
+    - 'unleash-client.gemspec'
+
+# Offense count: 13
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: with_first_argument, with_fixed_indentation
+Layout/AlignArguments:
+  Exclude:
+    - 'lib/unleash/configuration.rb'
+
+# Offense count: 45
+# Cop supports --auto-correct.
+# Configuration parameters: AllowMultipleStyles, EnforcedHashRocketStyle, EnforcedColonStyle, EnforcedLastArgumentHashStyle.
+# SupportedHashRocketStyles: key, separator, table
+# SupportedColonStyles: key, separator, table
+# SupportedLastArgumentHashStyles: always_inspect, always_ignore, ignore_implicit, ignore_explicit
+Layout/AlignHash:
+  Exclude:
+    - 'examples/simple.rb'
+    - 'lib/unleash/client.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+
+# Offense count: 10
+# Cop supports --auto-correct.
+Layout/BlockEndNewline:
+  Exclude:
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Layout/ClosingParenthesisIndentation:
+  Exclude:
+    - 'examples/simple.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Layout/CommentIndentation:
+  Exclude:
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 3
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: leading, trailing
+Layout/DotPosition:
+  Exclude:
+    - 'spec/unleash/client_spec.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+Layout/EmptyLineAfterGuardClause:
+  Exclude:
+    - 'lib/unleash/feature_toggle.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Layout/EmptyLineAfterMagicComment:
+  Exclude:
+    - 'unleash-client.gemspec'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: AllowAdjacentOneLineDefs, NumberOfEmptyLines.
+Layout/EmptyLineBetweenDefs:
+  Exclude:
+    - 'lib/unleash/client.rb'
+
+# Offense count: 14
+# Cop supports --auto-correct.
+Layout/EmptyLines:
+  Exclude:
+    - 'bin/unleash-client'
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/configuration.rb'
+    - 'lib/unleash/variant_definition.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/client_specification_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+    - 'spec/unleash/metrics_spec.rb'
+    - 'spec/unleash_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: around, only_before
+Layout/EmptyLinesAroundAccessModifier:
+  Exclude:
+    - 'lib/unleash/client.rb'
+
+# Offense count: 8
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: empty_lines, no_empty_lines
+Layout/EmptyLinesAroundBlockBody:
+  Exclude:
+    - 'spec/unleash/client_specification_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+    - 'spec/unleash/metrics_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_sessionid_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_userid_spec.rb'
+    - 'spec/unleash/strategy/util_spec.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: empty_lines, empty_lines_except_namespace, empty_lines_special, no_empty_lines, beginning_only, ending_only
+Layout/EmptyLinesAroundClassBody:
+  Exclude:
+    - 'lib/unleash/configuration.rb'
+    - 'lib/unleash/variant.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Layout/EmptyLinesAroundMethodBody:
+  Exclude:
+    - 'lib/unleash/metrics_reporter.rb'
+
+# Offense count: 7
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: empty_lines, empty_lines_except_namespace, empty_lines_special, no_empty_lines
+Layout/EmptyLinesAroundModuleBody:
+  Exclude:
+    - 'lib/unleash.rb'
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/context.rb'
+    - 'lib/unleash/metrics.rb'
+    - 'lib/unleash/metrics_reporter.rb'
+    - 'lib/unleash/scheduled_executor.rb'
+    - 'lib/unleash/toggle_fetcher.rb'
+
+# Offense count: 3
+# Cop supports --auto-correct.
+# Configuration parameters: AllowForAlignment, AllowBeforeTrailingComments, ForceEqualSignAlignment.
+Layout/ExtraSpacing:
+  Exclude:
+    - 'lib/unleash/configuration.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/strategy/base_spec.rb'
+
+# Offense count: 8
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: special_inside_parentheses, consistent, align_braces
+Layout/IndentFirstHashElement:
+  Exclude:
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: Width, IgnoredPatterns.
+Layout/IndentationWidth:
+  Exclude:
+    - 'lib/unleash/client.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Layout/LeadingBlankLines:
+  Exclude:
+    - 'lib/unleash/variant.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: AllowDoxygenCommentStyle.
+Layout/LeadingCommentSpace:
+  Exclude:
+    - 'lib/unleash/feature_toggle.rb'
+
+# Offense count: 10
+# Cop supports --auto-correct.
+Layout/MultilineBlockLayout:
+  Exclude:
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 9
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: symmetrical, new_line, same_line
+Layout/MultilineMethodCallBraceLayout:
+  Exclude:
+    - 'examples/simple.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+
+# Offense count: 25
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: aligned, indented, indented_relative_to_receiver
+Layout/MultilineMethodCallIndentation:
+  Exclude:
+    - 'lib/unleash.rb'
+    - 'lib/unleash/feature_toggle.rb'
+    - 'lib/unleash/variant_definition.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: aligned, indented
+Layout/MultilineOperationIndentation:
+  Exclude:
+    - 'lib/unleash/feature_toggle.rb'
+
+# Offense count: 13
+# Cop supports --auto-correct.
+Layout/SpaceAfterColon:
+  Exclude:
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 10
+# Cop supports --auto-correct.
+Layout/SpaceAfterComma:
+  Exclude:
+    - 'bin/unleash-client'
+    - 'lib/unleash/metrics_reporter.rb'
+    - 'spec/unleash/context_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Layout/SpaceAfterNot:
+  Exclude:
+    - 'lib/unleash/toggle_fetcher.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: space, no_space
+Layout/SpaceAroundEqualsInParameterDefault:
+  Exclude:
+    - 'lib/unleash/feature_toggle.rb'
+
+# Offense count: 50
+# Cop supports --auto-correct.
+# Configuration parameters: AllowForAlignment.
+Layout/SpaceAroundOperators:
+  Exclude:
+    - 'lib/unleash/configuration.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/strategy/application_hostname_spec.rb'
+    - 'spec/unleash/strategy/user_with_id_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: AllowForAlignment.
+Layout/SpaceBeforeFirstArg:
+  Exclude:
+    - 'spec/unleash/strategy/base_spec.rb'
+
+# Offense count: 144
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, EnforcedStyleForEmptyBraces.
+# SupportedStyles: space, no_space, compact
+# SupportedStylesForEmptyBraces: space, no_space
+Layout/SpaceInsideHashLiteralBraces:
+  Exclude:
+    - 'lib/unleash/metrics.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/context_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+    - 'spec/unleash/strategy/application_hostname_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_random_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_sessionid_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_userid_spec.rb'
+    - 'spec/unleash/strategy/remote_address_spec.rb'
+    - 'spec/unleash/strategy/user_with_id_spec.rb'
+
+# Offense count: 20
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: space, no_space
+Layout/SpaceInsideParens:
+  Exclude:
+    - 'bin/unleash-client'
+    - 'examples/simple.rb'
+    - 'lib/unleash/context.rb'
+    - 'lib/unleash/feature_toggle.rb'
+    - 'spec/unleash/client_spec.rb'
+
+# Offense count: 7
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: final_newline, final_blank_line
+Layout/TrailingBlankLines:
+  Exclude:
+    - 'examples/simple.rb'
+    - 'spec/unleash/strategy/application_hostname_spec.rb'
+    - 'spec/unleash/strategy/base_spec.rb'
+    - 'spec/unleash/strategy/default_spec.rb'
+    - 'spec/unleash/strategy/remote_address_spec.rb'
+    - 'spec/unleash/strategy/user_with_id_spec.rb'
+    - 'spec/unleash/strategy/util_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: runtime_error, standard_error
+Lint/InheritException:
+  Exclude:
+    - 'lib/unleash/strategy/base.rb'
+
+# Offense count: 5
+Lint/RescueException:
+  Exclude:
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/scheduled_executor.rb'
+    - 'lib/unleash/toggle_fetcher.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Lint/UnneededRequireStatement:
+  Exclude:
+    - 'lib/unleash/toggle_fetcher.rb'
+
+# Offense count: 3
+# Cop supports --auto-correct.
+# Configuration parameters: IgnoreEmptyBlocks, AllowUnusedKeywordArguments.
+Lint/UnusedBlockArgument:
+  Exclude:
+    - 'bin/unleash-client'
+    - 'lib/unleash/configuration.rb'
+
+# Offense count: 6
+# Cop supports --auto-correct.
+# Configuration parameters: AllowUnusedKeywordArguments, IgnoreEmptyMethods.
+Lint/UnusedMethodArgument:
+  Exclude:
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/scheduled_executor.rb'
+    - 'lib/unleash/strategy/base.rb'
+    - 'lib/unleash/strategy/default.rb'
+
+# Offense count: 6
+Lint/UselessAssignment:
+  Exclude:
+    - 'bin/unleash-client'
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/strategy/gradual_rollout_random.rb'
+    - 'lib/unleash/toggle_fetcher.rb'
+    - 'spec/unleash/client_spec.rb'
+
+# Offense count: 17
+Metrics/AbcSize:
+  Max: 50
+
+# Offense count: 21
+# Configuration parameters: CountComments, ExcludedMethods.
+# ExcludedMethods: refine
+Metrics/BlockLength:
+  Max: 290
+
+# Offense count: 2
+# Configuration parameters: CountComments.
+Metrics/ClassLength:
+  Max: 105
+
+# Offense count: 8
+Metrics/CyclomaticComplexity:
+  Max: 19
+
+# Offense count: 28
+# Cop supports --auto-correct.
+# Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 120
+  Exclude:
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/context.rb'
+    - 'lib/unleash/feature_toggle.rb'
+    - 'lib/unleash/metrics_reporter.rb'
+    - 'lib/unleash/scheduled_executor.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 17
+# Configuration parameters: CountComments, ExcludedMethods.
+Metrics/MethodLength:
+  Max: 28
+
+# Offense count: 8
+Metrics/PerceivedComplexity:
+  Max: 20
+
+# Offense count: 2
+Naming/AccessorMethodName:
+  Exclude:
+    - 'lib/unleash/configuration.rb'
+    - 'lib/unleash/feature_toggle.rb'
+
+# Offense count: 1
+Naming/BinaryOperatorParameterName:
+  Exclude:
+    - 'lib/unleash/variant.rb'
+
+# Offense count: 1
+# Configuration parameters: MinNameLength, AllowNamesEndingInNumbers, AllowedNames, ForbiddenNames.
+# AllowedNames: io, id, to, by, on, in, at, ip, db
+Naming/UncommunicativeMethodParamName:
+  Exclude:
+    - 'lib/unleash/variant.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: prefer_alias, prefer_alias_method
+Style/Alias:
+  Exclude:
+    - 'lib/unleash/client.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: always, conditionals
+Style/AndOr:
+  Exclude:
+    - 'lib/unleash/configuration.rb'
+
+# Offense count: 14
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, ProceduralMethods, FunctionalMethods, IgnoredMethods, AllowBracesOnProceduralOneLiners.
+# SupportedStyles: line_count_based, semantic, braces_for_chaining, always_braces
+# ProceduralMethods: benchmark, bm, bmbm, create, each_with_object, measure, new, realtime, tap, with_object
+# FunctionalMethods: let, let!, subject, watch
+# IgnoredMethods: lambda, proc, it
+Style/BlockDelimiters:
+  Exclude:
+    - 'lib/unleash.rb'
+    - 'lib/unleash/feature_toggle.rb'
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+
+# Offense count: 21
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: braces, no_braces, context_dependent
+Style/BracesAroundHashParameters:
+  Exclude:
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/context_spec.rb'
+    - 'spec/unleash/strategy/application_hostname_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_random_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_userid_spec.rb'
+    - 'spec/unleash/strategy/remote_address_spec.rb'
+    - 'spec/unleash/strategy/user_with_id_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/ColonMethodCall:
+  Exclude:
+    - 'lib/unleash.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/DefWithParentheses:
+  Exclude:
+    - 'lib/unleash.rb'
+
+# Offense count: 22
+Style/Documentation:
+  Exclude:
+    - 'spec/**/*'
+    - 'test/**/*'
+    - 'lib/unleash.rb'
+    - 'lib/unleash/activation_strategy.rb'
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/configuration.rb'
+    - 'lib/unleash/context.rb'
+    - 'lib/unleash/feature_toggle.rb'
+    - 'lib/unleash/metrics.rb'
+    - 'lib/unleash/metrics_reporter.rb'
+    - 'lib/unleash/scheduled_executor.rb'
+    - 'lib/unleash/strategy/application_hostname.rb'
+    - 'lib/unleash/strategy/base.rb'
+    - 'lib/unleash/strategy/default.rb'
+    - 'lib/unleash/strategy/gradual_rollout_random.rb'
+    - 'lib/unleash/strategy/gradual_rollout_sessionid.rb'
+    - 'lib/unleash/strategy/gradual_rollout_userid.rb'
+    - 'lib/unleash/strategy/remote_address.rb'
+    - 'lib/unleash/strategy/user_with_id.rb'
+    - 'lib/unleash/strategy/util.rb'
+    - 'lib/unleash/toggle_fetcher.rb'
+    - 'lib/unleash/variant.rb'
+    - 'lib/unleash/variant_definition.rb'
+    - 'lib/unleash/variant_override.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+Style/EmptyLiteral:
+  Exclude:
+    - 'spec/unleash/context_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/Encoding:
+  Exclude:
+    - 'unleash-client.gemspec'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/ExpandPathArguments:
+  Exclude:
+    - 'unleash-client.gemspec'
+
+# Offense count: 49
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: always, never
+Style/FrozenStringLiteralComment:
+  Exclude:
+    - 'Gemfile'
+    - 'Rakefile'
+    - 'bin/console'
+    - 'bin/unleash-client'
+    - 'examples/simple.rb'
+    - 'lib/unleash.rb'
+    - 'lib/unleash/activation_strategy.rb'
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/configuration.rb'
+    - 'lib/unleash/context.rb'
+    - 'lib/unleash/feature_toggle.rb'
+    - 'lib/unleash/metrics.rb'
+    - 'lib/unleash/metrics_reporter.rb'
+    - 'lib/unleash/scheduled_executor.rb'
+    - 'lib/unleash/strategy/application_hostname.rb'
+    - 'lib/unleash/strategy/base.rb'
+    - 'lib/unleash/strategy/default.rb'
+    - 'lib/unleash/strategy/gradual_rollout_random.rb'
+    - 'lib/unleash/strategy/gradual_rollout_sessionid.rb'
+    - 'lib/unleash/strategy/gradual_rollout_userid.rb'
+    - 'lib/unleash/strategy/remote_address.rb'
+    - 'lib/unleash/strategy/user_with_id.rb'
+    - 'lib/unleash/strategy/util.rb'
+    - 'lib/unleash/toggle_fetcher.rb'
+    - 'lib/unleash/variant.rb'
+    - 'lib/unleash/variant_definition.rb'
+    - 'lib/unleash/variant_override.rb'
+    - 'lib/unleash/version.rb'
+    - 'spec/spec_helper.rb'
+    - 'spec/unleash/activation_strategy_spec.rb'
+    - 'spec/unleash/client_spec.rb'
+    - 'spec/unleash/client_specification_spec.rb'
+    - 'spec/unleash/configuration_spec.rb'
+    - 'spec/unleash/context_spec.rb'
+    - 'spec/unleash/feature_toggle_spec.rb'
+    - 'spec/unleash/metrics_spec.rb'
+    - 'spec/unleash/scheduled_executor_spec.rb'
+    - 'spec/unleash/strategy/application_hostname_spec.rb'
+    - 'spec/unleash/strategy/base_spec.rb'
+    - 'spec/unleash/strategy/default_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_random_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_sessionid_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_userid_spec.rb'
+    - 'spec/unleash/strategy/remote_address_spec.rb'
+    - 'spec/unleash/strategy/user_with_id_spec.rb'
+    - 'spec/unleash/strategy/util_spec.rb'
+    - 'spec/unleash/variant_override_spec.rb'
+    - 'spec/unleash_spec.rb'
+    - 'unleash-client.gemspec'
+
+# Offense count: 7
+# Configuration parameters: MinBodyLength.
+Style/GuardClause:
+  Exclude:
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/configuration.rb'
+    - 'lib/unleash/scheduled_executor.rb'
+    - 'lib/unleash/toggle_fetcher.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, UseHashRocketsWithSymbolValues, PreferHashRocketsForNonAlnumEndingSymbols.
+# SupportedStyles: ruby19, hash_rockets, no_mixed_keys, ruby19_no_mixed_keys
+Style/HashSyntax:
+  Exclude:
+    - 'Rakefile'
+
+# Offense count: 2
+# Configuration parameters: AllowIfModifier.
+Style/IfInsideElse:
+  Exclude:
+    - 'bin/unleash-client'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/IfUnlessModifier:
+  Exclude:
+    - 'lib/unleash/configuration.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: InverseMethods, InverseBlocks.
+Style/InverseMethods:
+  Exclude:
+    - 'lib/unleash.rb'
+
+# Offense count: 4
+# Cop supports --auto-correct.
+# Configuration parameters: IgnoredMethods.
+Style/MethodCallWithoutArgsParentheses:
+  Exclude:
+    - 'lib/unleash/feature_toggle.rb'
+    - 'lib/unleash/metrics_reporter.rb'
+    - 'spec/unleash/strategy/base_spec.rb'
+    - 'spec/unleash/strategy/default_spec.rb'
+
+# Offense count: 4
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: literals, strict
+Style/MutableConstant:
+  Exclude:
+    - 'lib/unleash/strategy/application_hostname.rb'
+    - 'lib/unleash/strategy/remote_address.rb'
+    - 'lib/unleash/strategy/user_with_id.rb'
+    - 'lib/unleash/version.rb'
+
+# Offense count: 1
+Style/NestedTernaryOperator:
+  Exclude:
+    - 'bin/unleash-client'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+# Configuration parameters: AutoCorrect, EnforcedStyle, IgnoredMethods.
+# SupportedStyles: predicate, comparison
+Style/NumericPredicate:
+  Exclude:
+    - 'spec/**/*'
+    - 'lib/unleash/strategy/gradual_rollout_sessionid.rb'
+    - 'lib/unleash/strategy/gradual_rollout_userid.rb'
+
+# Offense count: 2
+Style/OptionalArguments:
+  Exclude:
+    - 'lib/unleash/strategy/gradual_rollout_sessionid.rb'
+    - 'lib/unleash/strategy/gradual_rollout_userid.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/ParallelAssignment:
+  Exclude:
+    - 'lib/unleash/metrics_reporter.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+# Configuration parameters: PreferredDelimiters.
+Style/PercentLiteralDelimiters:
+  Exclude:
+    - 'unleash-client.gemspec'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/RedundantBegin:
+  Exclude:
+    - 'lib/unleash/toggle_fetcher.rb'
+
+# Offense count: 8
+# Cop supports --auto-correct.
+# Configuration parameters: AllowMultipleReturnValues.
+Style/RedundantReturn:
+  Exclude:
+    - 'lib/unleash/client.rb'
+    - 'lib/unleash/feature_toggle.rb'
+    - 'lib/unleash/metrics_reporter.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: ConvertCodeThatCanStartToReturnNil, Whitelist.
+# Whitelist: present?, blank?, presence, try, try!
+Style/SafeNavigation:
+  Exclude:
+    - 'lib/unleash/toggle_fetcher.rb'
+
+# Offense count: 3
+# Cop supports --auto-correct.
+# Configuration parameters: MinSize.
+# SupportedStyles: percent, brackets
+Style/SymbolArray:
+  EnforcedStyle: brackets
+
+# Offense count: 2
+# Cop supports --auto-correct.
+# Configuration parameters: IgnoredMethods.
+# IgnoredMethods: respond_to, define_method
+Style/SymbolProc:
+  Exclude:
+    - 'lib/unleash/feature_toggle.rb'
+    - 'lib/unleash/strategy/application_hostname.rb'
+
+# Offense count: 3
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyleForMultiline.
+# SupportedStylesForMultiline: comma, consistent_comma, no_comma
+Style/TrailingCommaInArguments:
+  Exclude:
+    - 'bin/unleash-client'
+    - 'examples/simple.rb'
+    - 'spec/unleash/context_spec.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyleForMultiline.
+# SupportedStylesForMultiline: comma, consistent_comma, no_comma
+Style/TrailingCommaInHashLiteral:
+  Exclude:
+    - 'bin/unleash-client'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/UnlessElse:
+  Exclude:
+    - 'lib/unleash/client.rb'
+
+# Offense count: 4
+# Cop supports --auto-correct.
+Style/UnneededInterpolation:
+  Exclude:
+    - 'spec/unleash/strategy/gradual_rollout_sessionid_spec.rb'
+    - 'spec/unleash/strategy/gradual_rollout_userid_spec.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+Style/UnneededPercentQ:
+  Exclude:
+    - 'unleash-client.gemspec'
+
+# Offense count: 5
+# Cop supports --auto-correct.
+# Configuration parameters: MinSize, WordRegex.
+# SupportedStyles: percent, brackets
+Style/WordArray:
+  EnforcedStyle: brackets
diff --git a/unleash-client.gemspec b/unleash-client.gemspec
index 0d9c28ea..d074446c 100644
--- a/unleash-client.gemspec
+++ b/unleash-client.gemspec
@@ -22,7 +22,7 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-  spec.required_ruby_version = "~> 2.2"
+  spec.required_ruby_version = "~> 2.3"
 
   spec.add_dependency "murmurhash3", "~> 0.1.6"
 
@@ -32,5 +32,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rspec-json_expectations", "~> 2.1"
   spec.add_development_dependency "webmock", "~> 3.0"
   spec.add_development_dependency "coveralls"
-
+  spec.add_development_dependency "rubocop"
 end