diff --git a/.hound.yml b/.hound.yml
new file mode 100644
index 0000000..7f3d303
--- /dev/null
+++ b/.hound.yml
@@ -0,0 +1,2 @@
+StringLiterals:
+  EnforcedStyle: single_quotes
\ No newline at end of file
diff --git a/lib/credit_card_validations/detector.rb b/lib/credit_card_validations/detector.rb
index a256672..625c496 100644
--- a/lib/credit_card_validations/detector.rb
+++ b/lib/credit_card_validations/detector.rb
@@ -119,7 +119,7 @@ def delete_brand(key)
       #create rule for detecting brand
       def add_rule(key, length, prefixes)
         unless brands.has_key?(key)
-          raise CreditCardValidations::Error.new("brand #{key} is undefined, please use #add_brand method")
+          raise Error.new("brand #{key} is undefined, please use #add_brand method")
         end
         length, prefixes = Array(length), Array(prefixes)
         brands[key][:rules] << {length: length, regexp: compile_regexp(prefixes), prefixes: prefixes}
diff --git a/lib/credit_card_validations/error.rb b/lib/credit_card_validations/error.rb
index 4638447..0738fd2 100644
--- a/lib/credit_card_validations/error.rb
+++ b/lib/credit_card_validations/error.rb
@@ -1,4 +1,4 @@
 module CreditCardValidations
   class Error < StandardError
   end
-end
\ No newline at end of file
+end
diff --git a/lib/credit_card_validations/factory.rb b/lib/credit_card_validations/factory.rb
index e38deaf..6e74223 100644
--- a/lib/credit_card_validations/factory.rb
+++ b/lib/credit_card_validations/factory.rb
@@ -12,13 +12,11 @@ module CreditCardValidations
   class Factory
     class << self
       def random(brand = nil)
-        if brand.nil?
-          brand = Detector.brands.keys.sample
-        else
-          raise CreditCardValidations::Error.new("Unsupported brand") if Detector.brands[brand].nil?
+        brand = Detector.brands.keys.sample if brand.nil?
+        if Detector.brands[brand].nil?
+          raise Error.new('Unsupported brand')
         end
         generate(Detector.brands[brand][:rules].sample)
-
       end
 
       def generate(rule)
diff --git a/lib/credit_card_validations/plugins/diners_us.rb b/lib/credit_card_validations/plugins/diners_us.rb
index 1f7023c..6c80c25 100644
--- a/lib/credit_card_validations/plugins/diners_us.rb
+++ b/lib/credit_card_validations/plugins/diners_us.rb
@@ -1,8 +1,6 @@
-# :diners_us:
-#   :rules:
-#     - :length:
-#       - 16
-#       :prefixes:
-#       - '54'
-#       - '55'
-CreditCardValidations.add_brand(:diners_us, {length: 16, prefixes: %w(54 55)}, {brand_name: 'Diners Club US'})
\ No newline at end of file
+CreditCardValidations.add_brand(
+  :diners_us,
+  { length: 16, prefixes: %w(54 55) },
+  brand_name: 'Diners Club US'
+)
+
diff --git a/lib/credit_card_validations/plugins/en_route.rb b/lib/credit_card_validations/plugins/en_route.rb
index 198e726..dbb969e 100644
--- a/lib/credit_card_validations/plugins/en_route.rb
+++ b/lib/credit_card_validations/plugins/en_route.rb
@@ -1 +1,5 @@
-CreditCardValidations.add_brand(:en_route, {length: 15, prefixes: %w(2014 2149)}, {skip_luhn: true})
\ No newline at end of file
+CreditCardValidations.add_brand(
+  :en_route,
+  { length: 15, prefixes: %w(2014 2149) },
+  skip_luhn: true
+)
diff --git a/lib/credit_card_validations/plugins/laser.rb b/lib/credit_card_validations/plugins/laser.rb
index 82919ea..8ff90a6 100644
--- a/lib/credit_card_validations/plugins/laser.rb
+++ b/lib/credit_card_validations/plugins/laser.rb
@@ -1,12 +1,4 @@
-# :laser:
-#   :rules:
-#     - :length:
-#       - 16
-#       - 17
-#       - 18
-#       - 19
-#      :prefixes:
-#        - '6304'
-#        - '6706'
-#        - '6771'
-CreditCardValidations.add_brand(:laser, {length: [16, 17, 18, 19], prefixes: %w(6304 6706 6771)})
\ No newline at end of file
+CreditCardValidations.add_brand(
+  :laser,
+  length: [16, 17, 18, 19], prefixes: %w(6304 6706 6771)
+)
diff --git a/lib/credit_card_validations/version.rb b/lib/credit_card_validations/version.rb
index 42fc94d..f281e72 100644
--- a/lib/credit_card_validations/version.rb
+++ b/lib/credit_card_validations/version.rb
@@ -1,3 +1,3 @@
 module CreditCardValidations
-  VERSION = "3.0.0"
+  VERSION = '3.0.0'
 end
diff --git a/lib/plugins/diners_us.rb b/lib/plugins/diners_us.rb
deleted file mode 100644
index 1f7023c..0000000
--- a/lib/plugins/diners_us.rb
+++ /dev/null
@@ -1,8 +0,0 @@
-# :diners_us:
-#   :rules:
-#     - :length:
-#       - 16
-#       :prefixes:
-#       - '54'
-#       - '55'
-CreditCardValidations.add_brand(:diners_us, {length: 16, prefixes: %w(54 55)}, {brand_name: 'Diners Club US'})
\ No newline at end of file
diff --git a/lib/plugins/en_route.rb b/lib/plugins/en_route.rb
deleted file mode 100644
index 198e726..0000000
--- a/lib/plugins/en_route.rb
+++ /dev/null
@@ -1 +0,0 @@
-CreditCardValidations.add_brand(:en_route, {length: 15, prefixes: %w(2014 2149)}, {skip_luhn: true})
\ No newline at end of file
diff --git a/lib/plugins/laser.rb b/lib/plugins/laser.rb
deleted file mode 100644
index 82919ea..0000000
--- a/lib/plugins/laser.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-# :laser:
-#   :rules:
-#     - :length:
-#       - 16
-#       - 17
-#       - 18
-#       - 19
-#      :prefixes:
-#        - '6304'
-#        - '6706'
-#        - '6771'
-CreditCardValidations.add_brand(:laser, {length: [16, 17, 18, 19], prefixes: %w(6304 6706 6771)})
\ No newline at end of file
diff --git a/spec/active_model_spec.rb b/spec/active_model_spec.rb
index 3889034..68f6d93 100644
--- a/spec/active_model_spec.rb
+++ b/spec/active_model_spec.rb
@@ -1,13 +1,13 @@
 require_relative 'test_helper'
 
-describe "ActiveModel Validator" do
+describe 'ActiveModel Validator' do
 
   let(:model) { CreditCard.new }
 
-  describe "Proc support" do
-    it "should be valid if brands from proc valid" do
+  describe 'Proc support' do
+    it 'should be valid if brands from proc valid' do
        card = model.dup
-       card.card_type =  "Master Card"
+       card.card_type = 'Master Card'
        card.number6 =  CreditCardValidations::Factory.random(:visa)
        card.valid?.must_equal false
        card.number6 =  CreditCardValidations::Factory.random(:mastercard)
@@ -15,8 +15,8 @@
     end
   end
 
-  describe "Any Brand" do
-    it "should be valid for all prepared valid numbers" do
+  describe 'Any Brand' do
+    it 'should be valid for all prepared valid numbers' do
       VALID_NUMBERS.each do |_, numbers|
         numbers.each do |number|
           card = model
@@ -28,8 +28,8 @@
     end
   end
 
-  describe "Except Amex and Maestro brand" do
-    it "should reject all other valid numbers" do
+  describe 'Except Amex and Maestro brand' do
+    it 'should reject all other valid numbers' do
       VALID_NUMBERS.except(:amex, :maestro).each do |_, numbers|
         card = model
         card.number = numbers.first
@@ -38,7 +38,7 @@
       end
     end
 
-    it "should accept using except options" do
+    it 'should accept using except options' do
       VALID_NUMBERS.except(:amex, :maestro).each do |_, numbers|
         card = model
         card.number3 = numbers.first
@@ -47,8 +47,8 @@
     end
   end
 
-  describe "Only Amex and Mestro brands" do
-    it "should accept amex and maestro brand if valid" do
+  describe 'Only Amex and Mestro brands' do
+    it 'should accept amex and maestro brand if valid' do
       VALID_NUMBERS.slice(:amex, :maestro).each do |_, numbers|
         card = model
         card.number = numbers.first
@@ -58,12 +58,12 @@
     end
   end
 
-  describe "Custom error message"  do
-    it "should allow custom message" do
+  describe 'Custom error message' do
+    it 'should allow custom message' do
       card = model
       card.number7 =  'wrong'
       card.valid?.must_equal false
-      card.errors[:number7].must_equal ["Custom message"]
+      card.errors[:number7].must_equal ['Custom message']
     end
   end
 
diff --git a/spec/credit_card_validations_spec.rb b/spec/credit_card_validations_spec.rb
index 447af28..edadcf6 100644
--- a/spec/credit_card_validations_spec.rb
+++ b/spec/credit_card_validations_spec.rb
@@ -7,29 +7,28 @@
     CreditCardValidations.reload!
   end
 
-  describe "MMI" do
-    it "should detect issuer category" do
+  describe 'MMI' do
+    it 'should detect issuer category' do
       d = detector(VALID_NUMBERS[:visa].first)
       d.issuer_category.must_equal CreditCardValidations::Mmi::ISSUER_CATEGORIES[d.number[0]]
     end
   end
 
-  describe "Luhn#valid?" do
+  describe 'Luhn#valid?' do
     let(:card_detector) {
       detector(VALID_NUMBERS[:unionpay].first)
     }
-    it "should call Luhn.valid? once" do
+    it 'should call Luhn.valid? once' do
       CreditCardValidations::Luhn.expects(:valid?).with(card_detector.number).once
       card_detector.valid?(:visa, :unionpay).must_equal true
     end
 
-    it "should call Luhn.valid? twice" do
+    it 'should call Luhn.valid? twice' do
       CreditCardValidations::Luhn.expects(:valid?).with(card_detector.number).twice
       card_detector.valid?(:visa, :mastercard).must_equal false
     end
 
-    it "should not call Luhn.valid?" do
-
+    it 'should not call Luhn.valid?' do
       CreditCardValidations::Luhn.expects(:valid?).never
       card_detector.valid?(:unionpay).must_equal true
     end
@@ -37,7 +36,7 @@
   end
 
 
-  it "should check luhn" do
+  it 'should check luhn' do
     VALID_NUMBERS.each do |brand, card_numbers|
       if has_luhn_check_rule?(brand)
         card_numbers.each do |number|
@@ -47,7 +46,7 @@
     end
   end
 
-  it "should check valid brand" do
+  it 'should check valid brand' do
     VALID_NUMBERS.each do |brand, card_numbers|
       card_numbers.each do |card_number|
         detector(card_number).send("#{brand}?").must_equal true
@@ -56,7 +55,7 @@
     end
   end
 
-  it "should check if card invalid" do
+  it 'should check if card invalid' do
     INVALID_NUMBERS.each do |card_number|
       detector(card_number).valid?.must_equal false
       detector(card_number).brand.must_be_nil
@@ -66,14 +65,14 @@
     end
   end
 
-  it "should detect by full brand name" do
+  it 'should detect by full brand name' do
     amex = CreditCardValidations::Factory.random(:amex)
     detector(amex).valid?('American Express').must_equal true
     visa = CreditCardValidations::Factory.random(:visa)
     detector(visa).valid?('American Express').must_equal false
   end
 
-  it "should support multiple brands for single check" do
+  it 'should support multiple brands for single check' do
     VALID_NUMBERS.slice(:visa, :mastercard).each do |key, value|
       detector(value.first).brand(:visa, :mastercard).must_equal key
     end
@@ -83,7 +82,7 @@
     end
   end
 
-  it "should check if valid brand without arguments" do
+  it 'should check if valid brand without arguments' do
     VALID_NUMBERS.each do |key, value|
       value.each do |card_number|
         detector(card_number).valid?(key).must_equal true
@@ -92,47 +91,47 @@
     end
   end
 
-  it "should not be valid? if wrong brand" do
+  it 'should not be valid? if wrong brand' do
     detector(VALID_NUMBERS[:visa].first).valid?(:mastercard).must_equal false
     detector(VALID_NUMBERS[:mastercard].first).valid?(:visa).must_equal false
   end
 
-  it "should  be valid? if right brand" do
+  it 'should  be valid? if right brand' do
     detector(VALID_NUMBERS[:visa].first).valid?(:mastercard, :visa).must_equal true
     detector(VALID_NUMBERS[:visa].first).valid?(:mastercard, :amex).must_equal false
   end
 
 
-  describe "adding/removing brand" do
+  describe 'adding/removing brand' do
 
-    describe "adding rules" do
+    describe 'adding rules' do
 
       let(:voyager_number) { '869926275400212' }
 
-      it "should validate number as voyager" do
-        CreditCardValidations::Detector.add_brand(:voyager, { length: 15, prefixes: '86' })
+      it 'should validate number as voyager' do
+        CreditCardValidations::Detector.add_brand(:voyager, length: 15, prefixes: '86')
         detector(voyager_number).valid?(:voyager).must_equal true
         detector(voyager_number).voyager?.must_equal true
         detector(voyager_number).brand.must_equal :voyager
       end
 
-      describe "Add voyager rule" do
+      describe 'Add voyager rule' do
         before do
-          CreditCardValidations::Detector.add_brand(:voyager, { length: 15, prefixes: '86' })
+          CreditCardValidations::Detector.add_brand(:voyager, length: 15, prefixes: '86')
         end
 
-        it "should validate number as voyager" do
+        it 'should validate number as voyager' do
           detector(voyager_number).valid?(:voyager).must_equal true
           detector(voyager_number).voyager?.must_equal true
           detector(voyager_number).brand.must_equal :voyager
         end
 
-        describe "Remove voyager rule" do
+        describe 'Remove voyager rule' do
           before do
             CreditCardValidations::Detector.delete_brand(:voyager)
           end
 
-          it "should not validate number as voyager" do
+          it 'should not validate number as voyager' do
             detector(voyager_number).respond_to?(:voyager?).must_equal false
             detector(voyager_number).brand.must_be_nil
           end
@@ -140,22 +139,24 @@
       end
     end
 
-    describe "plugins" do
-
+    describe 'plugins' do
       [:diners_us, :en_route, :laser].each do |brand|
         it "should support #{brand}" do
-          -> { CreditCardValidations::Factory.random(brand) }.must_raise(CreditCardValidations::Error)
-          detector('somenumber').respond_to?("#{brand}?").must_equal false
+          -> { CreditCardValidations::Factory.random(brand) }.
+            must_raise(CreditCardValidations::Error)
+          custom_number = 'some_number'
+          detector(custom_number).respond_to?("#{brand}?").must_equal false
           require "credit_card_validations/plugins/#{brand}"
           number = CreditCardValidations::Factory.random(brand)
-          CreditCardValidations::Detector.new(number).valid?("#{brand}".to_sym).must_equal true
-          detector('somenumber').respond_to?("#{brand}?").must_equal true
+          detector(number).valid?("#{brand}".to_sym).must_equal true
+          detector(custom_number).respond_to?("#{brand}?").must_equal true
         end
       end
     end
 
-    it "should raise Error if no brand added before" do
-      -> { CreditCardValidations::Detector::add_rule(:undefined_brand, 20, [20]) }.must_raise(CreditCardValidations::Error)
+    it 'should raise Error if no brand added before' do
+      -> { CreditCardValidations::Detector::add_rule(:undefined_brand, 20, [20]) }.
+        must_raise(CreditCardValidations::Error)
     end
   end
 
diff --git a/spec/factory_spec.rb b/spec/factory_spec.rb
index fd473c6..97b93ef 100644
--- a/spec/factory_spec.rb
+++ b/spec/factory_spec.rb
@@ -2,22 +2,17 @@
 
 describe CreditCardValidations::Factory do
 
-  it "should generate random brand" do
+  it 'should generate random brand' do
     number = CreditCardValidations::Factory.random
     CreditCardValidations::Detector.new(number).valid?.must_equal true
   end
 
   CreditCardValidations::Detector.brands.keys.sort.each do |key|
     describe "#{key}" do
-
       it "should generate valid #{key}" do
         number = CreditCardValidations::Factory.random(key)
         CreditCardValidations::Detector.new(number).valid?(key).must_equal true
       end
-
     end
   end
-
-
-
 end
\ No newline at end of file
diff --git a/spec/models/credit_card.rb b/spec/models/credit_card.rb
index 2a3913a..d89f6d0 100644
--- a/spec/models/credit_card.rb
+++ b/spec/models/credit_card.rb
@@ -1,18 +1,18 @@
 class CreditCard
   attr_accessor :number, :number2, :number3, :number4, :number5, :number6, :number7, :card_type
   include ActiveModel::Validations
-  validates :number, credit_card_number: {brands: [:amex, :maestro]} , allow_blank: true
-  validates :number2, credit_card_number: {only: [:amex, :maestro]},  allow_blank: true
-  validates :number3, credit_card_number: {except: [:amex, :maestro]} , allow_blank: true
-  validates :number4, credit_card_number: {brands: :any}  , allow_blank: true
-  validates :number5, credit_card_number: true , allow_blank: true
-  validates :number6, credit_card_number: { brands: ->(record){ record.supported_brand } } , allow_blank: true
-  validates :number7, credit_card_number: { message: "Custom message" } , allow_blank: true
+  validates :number, credit_card_number: { brands: [:amex, :maestro] }, allow_blank: true
+  validates :number2, credit_card_number: { only: [:amex, :maestro] }, allow_blank: true
+  validates :number3, credit_card_number: { except: [:amex, :maestro] }, allow_blank: true
+  validates :number4, credit_card_number: { brands: :any }, allow_blank: true
+  validates :number5, credit_card_number: true, allow_blank: true
+  validates :number6, credit_card_number: { brands: ->(record) { record.supported_brand } }, allow_blank: true
+  validates :number7, credit_card_number: { message: 'Custom message' }, allow_blank: true
 
   def supported_brand
     {
-      "Master Card" => :mastercard,
-      "Visa" => :visa
+      'Master Card' => :mastercard,
+      'Visa' => :visa
     }[self.card_type]
   end
 
diff --git a/spec/string_spec.rb b/spec/string_spec.rb
index 49812a8..95ccc10 100644
--- a/spec/string_spec.rb
+++ b/spec/string_spec.rb
@@ -1,22 +1,13 @@
 require_relative 'test_helper'
 require 'credit_card_validations/string'
 
-describe "String ext" do
+describe 'String ext' do
 
-  let(:mastercard) {
-    CreditCardValidations::Factory.random(:mastercard)
-  }
-
-  let(:visa) {
-    CreditCardValidations::Factory.random(:visa)
-  }
-
-  let(:invalid) {
-    INVALID_NUMBERS.sample
-  }
-
-  it "should allow detect brand for mastercard" do
+  let(:mastercard) { CreditCardValidations::Factory.random(:mastercard) }
+  let(:visa) { CreditCardValidations::Factory.random(:visa) }
+  let(:invalid) { INVALID_NUMBERS.sample }
 
+  it 'should allow detect brand for mastercard' do
     mastercard.credit_card_brand.must_equal :mastercard
     mastercard.credit_card_brand_name.must_equal 'MasterCard'
     mastercard.valid_credit_card_brand?(:mastercard).must_equal true
@@ -24,16 +15,14 @@
     mastercard.valid_credit_card_brand?(:visa, :amex).must_equal false
   end
 
-  it "should allow detect brand for visa" do
-
+  it 'should allow detect brand for visa' do
     visa.credit_card_brand.must_equal :visa
     visa.credit_card_brand_name.must_equal 'Visa'
     visa.valid_credit_card_brand?(:mastercard).must_equal false
     visa.valid_credit_card_brand?(:visa, :amex).must_equal true
   end
 
-  it "should not allow detect brand for invalid card" do
-
+  it 'should not allow detect brand for invalid card' do
     invalid.credit_card_brand.must_be_nil
     invalid.credit_card_brand_name.must_be_nil
     invalid.valid_credit_card_brand?(:mastercard).must_equal false