Fix adding identical metering rules on two labels

Fixes: Bug #1229075

Change-Id: Id86c83ec9c7af78fc08e662bb0a9202f0f759c0c
Pythonic method names for l3_agent unit tests

When review https://review.openstack.org/#/c/46863/, i find there
are some unconsistent method names in test_l3_agent.py, this patch
fixes this code style problem.

Change-Id: I0e657e02155e1fcd580f083f4b5ba56274eadf88
Partial-Bug: #1229155
Add host routes and dns nameservers to Midonet DHCP

In the Midonet plugin, the host routes and dns nameserver information
was not being passed down to the midonet client API. This fix addresses
this by passing down the correct information.

Change-Id: I142ad4ceccdcf8b0e13db55fa54513f82995efc5
Closes-Bug: #1229655
Merge "Add host routes and dns nameservers to Midonet DHCP"
Merge "Fix adding identical metering rules on two labels"
Merge "Pythonic method names for l3_agent unit tests"