Put py34 first in the env order of tox
Put py34 first in the env order of tox

To solve the problem of "db type could not be determined" on py34 we
have to run first the py34 env to, then, run py27.  This patch puts py34
first on the tox.ini list of envs to avoid this problem to happen.

Change-Id: I80b755d0aa18db7c55ccaecd1c4f64d4fe09b4c5
Closes-Bug: #1489059

NaohiroTamura/ironic-lib,openstack/ironic-lib