add binary in Skim.app Cask

Skim has three shared command line tools, displayline, skimnotes and
skimpdf. Other applications may need these binaries to interact with
Skim, for features like TeX-PDF Synchronization etc.
Update to version 0.3.0

Kitematic has just released a new version that solves some problems for people on Yosemite. https://github.com/kitematic/kitematic/issues/99#issuecomment-59678616
Merge pull request #6860 from paracycle/patch-1

Update Kitematic.app to v0.3.0
Merge pull request #6867 from fza/master

Edit Cocktail cask in order to use conditionals
Merge pull request #6861 from yipeipei/fix-skim-binary

add binary in Skim.app Cask