Applied fixes that allow tests to pass again.
Added exec command to homesick.
Merge pull request #97 from JCook21/exec

Added Exec command
Replace any system calls in lib that don't use git with calls to FileUtils
Replace a system call in the spec helper
Add the grit gem
Add a new RepoFinder module, along with new tests for it
Start using grit for commands that don't need to show git output