Get information from outside of the project

[pythonissam]

Under the current implementation, .git must be in the project. I suggest that we give git command the visibility of other directories in addition to the current directory.

[jneira]

Oh, afaik there is a mechanism to tell the lib where is the .git directory: putting a file named .git with the contents:

 gitdir: /path/to/custom/.git

see https://github.com/acfoltzer/gitrev/blob/450a7abf444260e95791649489705e54650c0232/src/Development/GitRev.hs#L112-L118