Fixed a typo

Fixed a variable name
updated composer to stable stability
Merge pull request #70 from mboie/master

updated composer to stable stability
Merge branch 'master' of https://github.com/CSC495-2014/TeamworkEnglewoodGit
Reverted back to two classes instead of three.
Successfully implemented the following classes: AbstractFileSystem, FileSystem, and GitCommands. I also fixed some commenting to mirrr PHP doc