Fix forgotten renaming in spec
Add changelog
Add CommandRunner
Rename RubocopLinter to Rubocop
Use PATH of login shell even if Atom is launched from Finder or Dock

This fixes #1.
Use config 'atom-lint.rubocop.path' if it's set

Related to #1.
Cache PATH of login shell
Merge branch 'handle-path-env'
Update changelog for 0.1.2
Prepare 0.1.2 release