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
Gracefully fail LockfileParserError and handle empty lockfiles
update error message that an error occured while reading the lockfile and

not that the file couldn't be read
Merge pull request #687 from RiotGames/lockfile_parser_error-master

Gracefully fail LockfileParserError and handle empty lockfiles
Merge branch 'master' into backport_lockfile_fixes

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

Forwardport lockfile fixes
Merge branch 'master' into fix_lockfile_speed-master
fix two failing lockfile features