The old fetch_branch() wasn't behaving properly with the ceph.com git
mirror. This method works with github.com and ceph.com. Add a couple
unit tests, and leave the old fetch_branch() in place for now, even
though nothing uses it.
Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Part of this is also about failing sooner, and not allowing invalid
configurations to enter the queue. This commit also fixes an obscure bug
in substitute_placeholders(). Finally, it adds unit tests for all bugs
fixed.
Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
