Git-interface

Added
- Read file from a repo
- `cat-file` command
- `rev-list` command
- Access git version

Changed
- Add parent hash and author name to log class

Fixed
- 2 - cat file commands not running

Added
- Read file
- Get object size
- Get object type
- Read object pretty printed

Fixed
- Fix bug with getting branch names

Added
- Cloning support (without authentication)

Fixed
- Fixed 1 `get_branches()` not showing full branch names

Added
- Project changelog
- Branch creation
- Branch copy
- Branch rename
- Branch deletion
- Ls-tree functionality
- Symbolic-ref functionality

Changed
- Add `NoBranchesException` to `get_branches()`

Fixed
- Add missing `__all__` methods