Big Switch: Check for 'id' in port before lookup

Check for the presence of the 'id' key before trying
to do a lookup based on the value. This is necessary
because a 'fields' param to get_port(s) may exclude
the 'id' field before the host_id lookup.

Closes-Bug: #1358668
Change-Id: If30567d5deaeabd2de6c6287fac7a81695a41cc5
Add requests_mock to test-requirements.txt

Already in global-requirements. Will use for VPN unit tests
(bug 116018).

Change-Id: I140caebd3bc4f4cbf9563698bf0143f68456c762
Closes-Bug: 1358472
Fix for floating ip association and deletion

Added code to associate fip to a vm in VSD, if
the fip was already associated with the vm port
in Neutron. Also added code in fip deletion,
to get the correct router id based on the check
if the fip is associated to a Neutron port or
not.
Closes-Bug: #1350469
Change-Id: I1aa24f420f656043086a4f501b15722216b843e9
Merge "Add requests_mock to test-requirements.txt"
Merge "Big Switch: Check for 'id' in port before lookup"
Merge "Fix for floating ip association and deletion"