Move subnet,port,router test files together, Add missing router-testcase from earlier commit

Change-Id: Iabf5cb4b35b04f7315ca82f9f0aee8d82a56a548
Merge remote-tracking branch 'upstream/test_parallelism' into test_parallelism
Merge remote-tracking branch 'upstream/test_parallelism' into test_parallelism
Added neutronapi tests and related infra changes for the same

Below tests are added
* to boot from specific subnet
* port to get a specific IP
* port to get a specific MAC
* port with no SG
* port with non-default SG
* Host route validation
* DNS validation
* Custom gateway
* Allocation pool

Change-Id: I0766507f5aae3d40cff284f2ca544e0702e66bbb
Merge pull request #35 from vedujoshi/test_parallelism

Added neutronapi tests and related infra changes for the same