Lock Rake to 12.2.x versions

This is for Ruby 1.9.3 compatibility, which Rake 12.3 no longer has (requiring minimum Ruby 2.0)

I18n 1.0 will no longer support 1.9.3, but we need to support it for the time being to not break backwards compatibility

Author: radar

Gemfile

@@ -4,5 +4,5 @@ gemspec
 
 gem 'mocha'
 gem 'test_declarative'
-gem 'rake'
+gem 'rake', '~> 12.2.1'
 gem 'minitest'