Clean up LOG import in floating_ips_bulk v2 api

Remove useless code of LOG in floating_ips_bulk.py

Change-Id: I66f20a23d75b2c9c2e7cc2425f015a95fefb62d8
Add unit test for add_floating_ip API

Currently, add_floating_ip API has no unit test for body's key test,
this patch adds the test cases.

Change-Id: I32a32514c68fcd8717011d37724a20993aa8ed20
Merge "Add unit test for add_floating_ip API"
Merge "Clean up LOG import in floating_ips_bulk v2 api"