Need better messages when git clone fails

[dpoirier]

If the repo is private and we try to clone it with an https: URL (instead of using a git URL and providing a key file), then ansible just hangs with no indication of what's going on. Maybe git is prompting or something; who knows?

If the branch we're trying to checkout doesn't exist, ansible just tells us the checkout failed, but not why.

There's also a warning in the docs (http://docs.ansible.com/ansible/git_module.html): "If the task seems to be hanging, first verify remote host is in known_hosts. SSH will prompt user to authorize the first contact with a remote host. To avoid this prompt, one solution is to add the remote host public key in /etc/ssh/ssh_known_hosts before calling the git module, with the following command: ssh-keyscan -H remote_host.com >> /etc/ssh/ssh_known_hosts.". -- It would be nice if we could find a way for that to fail with a useful message instead of hanging.

[dpoirier]

It looks like adding ssh_opts="-o StrictHostKeyChecking=no" to our git tasks might avoid one problem.