Fix other builds by pinning rest client (#1779)

* pin rubocop for rails

* limit relish to modern rubies

Author: JonRowe

Gemfile

@@ -11,7 +11,9 @@ gem 'yard', '~> 0.8.7', :require => false
 group :documentation do
   gem 'redcarpet',     '2.3.0'
   gem 'github-markup', '1.0.0'
-  gem 'relish'
+  if RUBY_VERSION > '2.0.0'
+    gem 'relish'
+  end
 end
 
 platforms :jruby do
@@ -57,9 +59,10 @@ if RUBY_VERSION <= '1.8.7'
   gem 'rubyzip', '< 1.0'
 end
 
-unless RUBY_VERSION >= '2.4.0'
+if RUBY_VERSION >= '2.0.0' && RUBY_VERSION < '2.2.0'
   # our current rubocop version doesnt support the json version required by Ruby 2.4
-  gem 'rubocop', "~> 0.23.0", :platform => [:ruby_20, :ruby_21]
+  # our rails rubocop setup only supports 2.0 and 2.1
+  gem 'rubocop', "~> 0.23.0"
 end
 
 custom_gemfile = File.expand_path("../Gemfile-custom", __FILE__)