Renamed Codex to CodexRepositoryFlat and extracted CodexRepositoryInterface
Added initial CodexRepositoryGit implementation
Fixed issues with CodexRepositoryGit linking
Brought code into spec with upstream master
CodexRepositoryGit now uses branches instead of tags
Each branch is now checked out
Added CacheTrait usage to Git driver
Added short initial blurb about the git driver
Added caching and pull mechanism to CodexRepositoryGit
Added inadvertently deleted docs
Merge pull request #12 from veonik/git-strategy

[WIP] Git driver