KSENROLL-14743 Try to include base stable commit for sql changes testing

In order to test if the diff of a commit contains changes we need
the base commit.

So increase the depth by one to try and include the base commit.
KSENROLL-14743 Change PushGitReferenceMojo to use JGit to push the ref

We read in the environment variable for the github username and password
and then use those credentials with the JGit PushCommand.

This works to push the reference to the remote side.