fix typo for URL in spec doc
[Specification::DSL] Add a docset url attribute

https://github.com/CocoaPods/CocoaPods/issues/1699
Merge pull request #59 from CocoaPods/docset_url

[Specification::DSL] Add a docset url attribute
Remove extra comma and underscores
Merge pull request #60 from carsonmcdonald/lintermessagefix

Remove extra comma and underscores
[Podfile] Clarify ~> operator.

Fixes https://github.com/CocoaPods/CocoaPods/issues/1793
Change
Merge pull request #62 from dhoerl/master

Change back single quote to normal single quote
[Lockfile] Make sure file descriptor is closed.

Tip of the ‘ol hat to @floere for finding this.
[Readme] Use retina badge for Travis
[Readme] Make all the badges retina
Update README.md
[Rubocop] Require comma after last item of a list
[Gemfile] Don't user kicker from git
Fusion between the machine and the human to fix style... thanks Rubocop
[Rubocop] Ignore underscore in file name, for now
[Rakefile] Migrate release to Rainforest
Release 0.30.0
Check homepage accessible in lint
Maintain 1.8.7 syntax compatibility