Arrange compute nodes in hostname order

Arrange compute nodes in hostname order

The below is how a current job looks. Notice the CMP2_HOSTNAME with -0
maps to COMPUTE_2_IP and smae for the other vm. So we swap the
two HOSTNAME's and then they align with what is passed to pybot.
Without this, mentally when looking at debugs, you have to remember
to swap the two.

OS_CMP1_HOSTNAME: releng-17212-771-2-devstack-ocata-1.vexxhost.net -
OS_CMP1_IP: 10.30.170.121 - OS_COMPUTE_1_IP: 10.30.170.121
OS_CMP2_HOSTNAME: releng-17212-771-2-devstack-ocata-0.vexxhost.net -
OS_CMP2_IP: 10.30.170.13 - OS_COMPUTE_2_IP: 10.30.170.13

Change-Id: Ifab24ca30c24523f35591517338af7e9946d072e
Signed-off-by: Sam Hague <shague@redhat.com>