Added indices for ports.name and tenant_id

Addresses a portion of #75 by adding indices on quark_ports.name and
tenant_id based on some temporary tables we see being written to disk
during our scale testing. While I can't guarantee these are the
particular tables causing the issues (our version of MySQL only logs
that they were created, not what the query was) I tested locally I saw
use of the index and the disk temporary table counter wasn't incremented.
Merge pull request #76 from Cerberus98/master

Added indices for ports.name and tenant_id