Add LaunchBar cask
Merge pull request #189 from mfilej/launch-bar-5.4.2

Add LaunchBar cask
make the Cask DSL resilient to unexpected methods

will help with introducing and removing features, since the Cask
definitions move with every `brew update` and track master but the code
to handle them requires an explicit release and a `brew upgrade brew-cask`

relates to #179
build fixes
missed a spot
bump version to v0.8.0
Add AirServer cask
add audits into the build process

this way travis will be able to cover incoming pull requests of new
casks by running the audit on them. cool!

also:

- add checksums to audit
- fix missing checksums
Merge pull request #190 from mfilej/air-server-4.6.4

Add AirServer cask