Added GutterJsonOutput as a coverage service.

This allows seeing the raw gcov output next to your code inside Xcode,
using https://github.com/neonichu/PuncoverPlugin.
Added colors to the generated JSON.
Merge pull request #24 from neonichu/gutter-json

Added GutterJsonOutput as a coverage service.
Version 1.3.0
Implement a CocoaPods plugin
Add spec for cobertura xml coverage service.
Add cobertura xml coverage service.
Add nokogiri to Gemfile.
Add basic setup of cobertura report file.
Add subtype of CoverageFile named CoberturaCoverageFile.

Contains simple parser to bundle the file's lines of code by methods.
TODOs:
- ignore comments inside methods
- skip lines between '/*' and '*/'
Add simple implementation of cobertura xml generator.
Use Nokogiri::XML::Builder to create xml document.
Refactor and fix parser bugs.
Improve pattern matching.
Add TODOs.
Set correct filename and class name in xml class node.
Set correct filename and class name in xml class node.
Merge branch 'feature/cobertura_reporter' of github.com:tarbrain/slather into feature/cobertura_reporter
Cleanup code.
Refactor method parser.