Add integration test for creating an identity zone

Signed-off-by: Rob Szumlakowski <rszumlakowski@pivotal.io>
Move ServerRunning to the common jar

Signed-off-by: Rob Gallagher <rgallagher@pivotallabs.com>
Signed-off-by: Rob Szumlakowski <rszumlakowski@pivotal.io>
Add api for creating zones

[#81978984] https://www.pivotaltracker.com/story/show/81978984

Signed-off-by: Rob Gallagher <rgallagher@pivotallabs.com>
Signed-off-by: Rob Szumlakowski <rszumlakowski@pivotal.io>
Remove unused test.
Add description to IdentityZone.

[#82411992] https://www.pivotaltracker.com/story/show/82411992
Handle creating zones with duplicate domains.
- Change zones endpoint path from underscores to dashes.
- Rename createZone() to create()

[#82411992] https://www.pivotaltracker.com/story/show/82411992
Fixed IdentityZone fixture method to properly set the serviceInstanceId
of a zone, which must be unique. 
Also, ZoneAlreadyExistsException has a better error message that
actually contains the column where a constraint violation occured.
changed identity_zone.subdomain to identity_zone.hostname. This makes
zone resolution logic simpler and more generic. The intent is that the
hostname column will contain the entire hostname used in a request.
removed service_instance_id, we can use the id column for that.
Going back to using subdomain
setting ID in integration test
[#82411992] ID must be in the url and we only use PUTs for creation,
like the service broker API. Can't write more tests until update and get
is implemented.