Depending on how things merge into a branch, the --first-parent option
might give us the wrong version. For example, python-troveclient at
26425a6 was showing 2.13.0 instead of the correct 2.14.0. Remove the
option to fix that problem.
Change-Id: I9a6996b03dc74df6963ac96887356bc6094e59b7
Signed-off-by: Doug Hellmann <doug@doughellmann.com>