TestPolicyAddDelete fails with Go 1.7

TestPolicyAddDelete is failing with Go 1.7. This needs more investigation to figure out what's going on.

```
--- FAIL: TestPolicyAddDelete (2.29s)
ofnetPolicy_test.go:161: Could not find the flow priority=110,tcp,metadata=0x640190/0x7ffffffe,nw_src=10.10.10.0/24,nw_dst=10.1.1.0/24,tp_src=200,tp_dst=100 on ovs ovsbr60
```