Docs: Run py34 tox test before py27
Docs: Run py34 tox test before py27

Since running the py27 tox test before the py34 tox test can cause
errors about 'db type could not be determined'. Change the docs to
show the py34 test first, so hopefully people will run that test
first.

Change-Id: I59409edc5cab7f58112ebe28e280f0eeda3becd0

SauloAislan/ironic,openstack/ironic,SauloAislan/ironic,pshchelo/ironic,NaohiroTamura/ironic,openstack/ironic,pshchelo/ironic,NaohiroTamura/ironic