This patch adds api sample tests and api samples for availability_zone.
Because the detail's response use host name as the key of dict and samples
tests didn't support replacing key with variable, so startup nova's service
with specific hostname instead of uuid.
Partially implements blueprint v3-api-unittests
Partially implements blueprint v3-api-specification
Change-Id: I9090a73a8293f26d63744a10d7ffbfc887e37e7c
4d293357b7