_f5.py does not handle policies correctly
_f5.py does not handle policies correctly

Problem:
The expectation that policy rules must have conditions is not correct;
and policy changes on virtual servers were not being detected.

Solution:
1. Made conditions optional as they are optional on the Big-IP.
2. Updated virtual_update() to check the policy names and update the
Big-IP accordingly.

Fixes #99

affects-branches: master

f5devcentral/f5-cccl,ryan-talley/f5-cccl,ryan-talley/f5-cccl,richbrowne/f5-cccl,f5devcentral/f5-cccl,richbrowne/f5-cccl