Move RuboCop dependencies to Gemfile

Speed up CI specs by moving RuboCop to an independent build. This will
also prevent issues when RuboCop will drop EOL rubies.

For the moment, this change is enough to keep supporting Ruby 2.4

Ref: rubocop/rubocop#9648

.travis.yml

@@ -43,6 +43,11 @@ jobs:
     # TODO: Remove when 6.0 stable will ship rails/rails#39697
     - rvm: 3.0.1
       gemfile: gemfiles/rails_6.0.gemfile
+  include:
+    - rvm: 2.4.10
+      gemfile: Gemfile
+      script: bundle exec rake rubocop
+      name: RuboCop
   exclude:
     - rvm: 2.4.10
       gemfile: gemfiles/rails_6.1.gemfile
@@ -74,4 +79,4 @@ jobs:
       gemfile: gemfiles/rails_5.2.gemfile
   fast_finish: true
 
-script: bundle exec rake test:all
+script: bundle exec rake test:ruby test:js

Gemfile

@@ -4,3 +4,9 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in client_side_validations.gemspec
 gemspec
+
+gem 'rubocop', '~> 1.12.1'
+gem 'rubocop-minitest', '~> 0.11.1'
+gem 'rubocop-performance', '~> 1.10.2'
+gem 'rubocop-rails', '~> 2.9'
+gem 'rubocop-rake', '~> 0.5.1'

client_side_validations.gemspec

@@ -36,11 +36,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'minitest', '~> 5.14'
   spec.add_development_dependency 'mocha', '~> 1.12'
   spec.add_development_dependency 'rake', '~> 13.0'
-  spec.add_development_dependency 'rubocop', '~> 1.12'
-  spec.add_development_dependency 'rubocop-minitest', '~> 0.11.0'
-  spec.add_development_dependency 'rubocop-performance', '~> 1.10'
-  spec.add_development_dependency 'rubocop-rails', '~> 2.9'
-  spec.add_development_dependency 'rubocop-rake', '~> 0.5.1'
   spec.add_development_dependency 'simplecov', '>= 0.18.5', '< 0.22'
   spec.add_development_dependency 'sqlite3', '~> 1.4'
 

gemfiles/rails_5.0.gemfile

@@ -2,6 +2,11 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 1.12.1"
+gem "rubocop-minitest", "~> 0.11.1"
+gem "rubocop-performance", "~> 1.10.2"
+gem "rubocop-rails", "~> 2.9"
+gem "rubocop-rake", "~> 0.5.1"
 gem "rails", "~> 5.0.0"
 gem "sqlite3", "~> 1.3.6"
 

gemfiles/rails_5.1.gemfile

@@ -2,6 +2,11 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 1.12.1"
+gem "rubocop-minitest", "~> 0.11.1"
+gem "rubocop-performance", "~> 1.10.2"
+gem "rubocop-rails", "~> 2.9"
+gem "rubocop-rake", "~> 0.5.1"
 gem "rails", "~> 5.1.0"
 gem "sqlite3", "~> 1.3.6"
 

gemfiles/rails_5.2.gemfile

@@ -2,6 +2,11 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 1.12.1"
+gem "rubocop-minitest", "~> 0.11.1"
+gem "rubocop-performance", "~> 1.10.2"
+gem "rubocop-rails", "~> 2.9"
+gem "rubocop-rake", "~> 0.5.1"
 gem "rails", "~> 5.2.0"
 
 gemspec path: "../"

gemfiles/rails_6.0.gemfile

@@ -2,6 +2,11 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 1.12.1"
+gem "rubocop-minitest", "~> 0.11.1"
+gem "rubocop-performance", "~> 1.10.2"
+gem "rubocop-rails", "~> 2.9"
+gem "rubocop-rake", "~> 0.5.1"
 gem "rails", "~> 6.0.0"
 
 gemspec path: "../"

gemfiles/rails_6.1.gemfile

@@ -2,6 +2,11 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 1.12.1"
+gem "rubocop-minitest", "~> 0.11.1"
+gem "rubocop-performance", "~> 1.10.2"
+gem "rubocop-rails", "~> 2.9"
+gem "rubocop-rake", "~> 0.5.1"
 gem "rails", "~> 6.1.0.rc1"
 
 gemspec path: "../"

gemfiles/rails_edge.gemfile

@@ -2,6 +2,11 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 1.12.1"
+gem "rubocop-minitest", "~> 0.11.1"
+gem "rubocop-performance", "~> 1.10.2"
+gem "rubocop-rails", "~> 2.9"
+gem "rubocop-rake", "~> 0.5.1"
 gem "rails", git: "https://github.com/rails/rails.git", branch: "main"
 
 gemspec path: "../"