Introduce GPG operations

Add methods for cryptographic authentication of Cask packages with
the GPG software suite.

Homebrew Cask invokes the system-standard `gpg` binary to import
keys to the GPG keychain, download signatures to versioned metadata
folders, and verify packages. Homebrew Cask aborts if any step fails.

GPG verification is not currently invoked during the audit or
installation processes, and is intentionally left undocumented.

Example usage:
    gpg = Cask::GpgCheck.new(cask)
    gpg.verify(package_archive_path) if gpg.available
Change app to "Timer.app"

Closes #7624.
Update AirParrot to v2
Merge pull request #7626 from jalaziz/update-airparrot

Update AirParrot to v2
Merge pull request #7625 from vitorgalvao/fix-7624

Change app to "Timer.app"
Add binary stanza to Vico.app Cask

Closes #7627.
Merge pull request #7628 from vitorgalvao/fix-7627

Add binary stanza to Vico.app Cask
Update razorsql to version 6.3.14
Upgraded Adapter to 2.1.3
Merge pull request #7633 from crainiarc/adapter

Upgraded Adapter to 2.1.3
Merge pull request #7632 from jrhe/master

Update razorsql to version 6.3.14
Add Soundnode-App.app version 0.4.0
Merge pull request #7635 from vinkla/soundnode-app

Add Soundnode-App.app version 0.4.0
Update RapidWeaver.app to version 6.0.3
updated leap-motion ('2.2.0')
Merge pull request #7629 from vinkla/rapidweaver

Update RapidWeaver.app to version 6.0.3
Merge pull request #7636 from vitorgalvao/update-leap-motion

updated leap-motion ('2.2.0')
re-use version in armitage
re-use version in astah-community
re-use version in colorport