Update rubocop, run it before specs

.rubocop.yml

@@ -1,112 +1,4 @@
-# Use `rubocop --display-cop-names` and consult
-# https://github.com/bbatsov/rubocop/blob/master/config/default.yml
-# for options.
+inherit_from: .rubocop_todo.yml
 
-# > Literal true appeared in a condition.
-# The `while do break` loop is not my favorite type of loop
-# either, but it's a valid technique and shouldn't be a lint
-# error.  At worst, it should be a style recommendation.
-# Finally, there is a `loop do .. end` alternative to `while true`
-# but it's nearly 3x slower. (https://www.ruby-forum.com/topic/179264)
-Lint/LiteralInCondition:
-  Enabled: false
-
-# TODO: Resolve, then increase severity
-Metrics/AbcSize:
-  Severity: refactor
-
-# TODO: Resolve, then increase severity
-Metrics/CyclomaticComplexity:
-  Severity: refactor
-
-Metrics/LineLength:
-  Max: 100 # TODO: Reduce to 80
-
-# TODO: Resolve, then increase severity
-Metrics/MethodLength:
-  Severity: refactor
-
-# TODO: Resolve, then increase severity
-Metrics/PerceivedComplexity:
-  Severity: refactor
-
-# Besides being racist, this also prevents the use of mathematical
-# symbols like π.  We're using utf-8 for a reason, c'mon.
-Style/AsciiComments:
-  Enabled: false
-
-# Block style should express the presence or absence of
-# side-effects, not the length of the block.
-Style/Blocks:
-  Enabled: false
-
-# An empty else clause is a good place to put comments explaining
-# a no-op.
-Style/EmptyElse:
-  Enabled: false
-
-# We can't say, in all cases that a guard clause is more
-# readable.  It should be left to the discretion of the
-# programmer.
-Style/GuardClause:
-  Enabled: false
-
-# > Favor modifier if usage when having a single-line body.
-# Yes, but there are still times, even with very short lines,
-# where a multi-line conditional is more readable.  Should
-# be left to the discretion of the programmer.
-Style/IfUnlessModifier:
-  Enabled: false
-
-# Normally I'd agree, but `loop` is nearly 3x slower, so we can't
-# use it in this performance-sensitive application.
-# (https://www.ruby-forum.com/topic/179264)
-Style/InfiniteLoop:
-  Enabled: false
-
-# > Align the operands of a condition in an unless statement
-# > spanning multiple lines.
-# This kind of style recommendation leads to too much mind-numbing
-# text shuffling.  It's not worth the "whitespace maintenance".
-Style/MultilineOperationIndentation:
-  Enabled: false
-
-# > Use next to skip iteration.
-# I agree, but this cop produces false positives.
-Style/Next:
-  Enabled: false
-
-# Normally, I'd agree, but `nil?` is actually a tiny bit slower,
-# and that matters when implementing algorithms.
-Style/NilComparison:
-  Enabled: false
-
-# String literal quoting has no impact on performance or
-# legibility.
-Style/StringLiterals:
-  Enabled: false
-
-# Percent-literal delimiters should express the content
-# of the literal, for example using square braces in `%w[]` to
-# indicate an array.
-Style/PercentLiteralDelimiters:
-  Enabled: false
-
-# > The RedundantReturn cop doesn't allow you to specify a return
-# > statement as the last line. But if the point is to return
-# > several values, I think return a, b, reads better than [a, b]
-# > https://github.com/bbatsov/rubocop/issues/528
-Style/RedundantReturn:
-  AllowMultipleReturnValues: true
-
-# Use space inside range literals.
-# Bad: `(a..b - 1)`
-# Good: `(a .. b - 1)`
-# All other binary operators in the language  (`+`, `<<`) have
-# spaces around them, so `..` and `...` should too.
-Style/SpaceInsideRangeLiteral:
-  Enabled: false
-
-# Disagree. Indentation of loops is an important visual clue.
-Style/WhileUntilModifier:
-  Enabled: false
+AllCops:
+  TargetRubyVersion: 2.0