Revert e84b189
Include all sources in the SHA calculation
Update documentation to reflect changes
Read all SHAs
Need to read an actual file...
Only calculate a git ref if one wasn't given at initialization
Merge branch 'master' into backport_lockfile_fixes

Conflicts:
	lib/berkshelf/lockfile.rb
Merge pull request #681 from RiotGames/backport_lockfile_fixes

Forwardport lockfile fixes