Release new version containing 9f9bce7

[radar]

When installing Rugged 1.5.1, it cannot find the right version of libgit2 when using --use-system-libraries. This is because 9f9bce7 this commit is missing from the released version.

Please release a new version of Rugged with this commit included.

[ioquatix]

I would also like this, I have to fork the repo and install the latest code (gem build and gem install) to get it to work :(

cc @carlosmn