Merge pull request #2846 from jk/feature/cert-quicklook

Add cert-quicklook v3
Merge pull request #2844 from ikebe/dragondisk-cask

add DragonDisk.app v1.05
don't choke when :args is not present

in _process_options
allow command.run without arguments

ie only an exectuable
test valid keys in _process_options

add monkeypatch on Hash in utils.rb for `assert_valid_keys` method
Add Xslimmer.app v1.9.4
Merge pull request #2853 from MattiSG/xslimmer

Add Xslimmer.app v1.9.4
Transmit 4.4.6
Merge pull request #2854 from ahbeng/transmit

Transmit 4.4.6
Merge pull request #2850 from rolandwalker/devscript_update

Devscript update
Merge pull request #2848 from lgarron/treemaker

Added TreeMaker 5.
Upgrade tor-browser to 3.5.2
Merge pull request #2856 from joelpurra/tor-browser-3.5.2

Upgrade tor-browser to 3.5.2
Add thong v1.1
Merge pull request #2857 from jk/feature/thong

Add thong v1.1
Merge pull request #2759 from rolandwalker/cleanup_cmd

add command `brew cask cleanup`
RStudio v0.98.501
Merge pull request #2851 from rolandwalker/system_command_followups

System command followups
Merge pull request #2858 from aaronwolen/master

RStudio v0.98.501
Update Light Table to 0.6.3