Support Rainbow gem both 1.99.x and 2.x

This fixes #762.
Merge pull request #763 from yujinakayama/support-rainbow-2

Support Rainbow gem both 1.99.x and 2.x
Fix incorrect check for existence of an instance method
[Fix #714] New cop RequireParentheses.
Merge pull request #756 from jonas054/require_parentheses

[Fix #714] New cop RequireParentheses.
[Fix #764] Handle heredocs in TrailingComma

There was a bug that made the cop consider commas inside heredocs as
trailing commas if the heredoc was part of the last item in a list.
Merge pull request #765 from jonas054/fix_trailing_comma_heredoc

[Fix #764] Handle heredocs in TrailingComma
Support auto-correction in WordArray.

Part of solution for #743.
Merge pull request #766 from jonas054/autocorrect_word_array

Support auto-correction in WordArray
Support mocked file paths in the spec helper's parse_source
Support for requires and generic options from rake tasks
Lazy load as much as possible
Rake task now supports `requires` and `options`
Merge pull request #767 from nevir/spec-file-helper

Support mocked file paths in the spec helper's parse_source
Merge pull request #768 from nevir/rake-requires

Rake task now supports `requires` and `options`
Don't double-append options :(
Merge pull request #770 from nevir/bugfix-for-768

Bugfix for #768
[Fix #761] Relax required json version to >= 1.7.7
[#743] Implement auto-correct for Proc cop
Excludes/includes support globs relative to the project (PWD for now).