Fixing Response code for POST token

API docs for Identity V3 has invalid response Code.
In the tokens section, for creating a token, its says:
the "Normal Response Codes" is 200, but the normal response code
is 201.

Closes-bug: #1330026
Change-Id: Id65b97d65299f4e7194a687b37bea1065ac30699
Merge "Fixing Response code for POST token"