Cartfile.lock

[jspahrsummers]

We need a file to track which versions we resolved for dependencies, so checking out a past commit results in consistent dependency versions everytime.

[jspahrsummers]

Although this is an internal Carthage file that should not be edited by users, it will be committed to their repositories, so changes to it should yield human-readable diffs.

This could probably look similar to the Cartfile itself, but with stricter syntax and fewer adornments:

ReactiveCocoa == 2.3.1
Mantle == 1.0
libextobjc == 0.4.1
xcconfigs == 0.5.1