convenient constructor especially for testing
[FIXED JENKINS-19108]

JGit was not honoring the branch in the checkoutBranch method
Need to explicitly add a test dep on sshd.
git-server plugin has a provided dependency on this, but Maven does not consider these to be transitive.
[FIXED JENKINS-18988]

CGit's checkout --force is behaving differently from JGit's checkout --force, so handle the difference by ourselves
Upgrading to the latest version
Adding the --shared option
[maven-release-plugin] prepare release git-client-1.3.0
[maven-release-plugin] prepare for next development iteration