On github comment on lintapp behalf

It seems only users can comment on github.
Applications are not allowed to do that (or I couldn't
find how to do that).

To work around this problem I created a github user
http://github.com/lintapp and post comments on its
behalf.

This works for public repos but does not for private ones.
Merge pull request #46 from X8/comment_on_lintapp_behalf

On github comment on lintapp behalf