Expanded assertion in test_create_token for keystone v2, v3

TokensTest.test_create_token and TokensV3Test.test_create_token
tests had very small validation of created token.
Added more assertion to TokensTest.test_create_token and
TokensV3Test.test_create_token tests.
Tests validate token expiration, token type, its user's name, id.
For Keystone V3 there is also validateion for method of token.

Change-Id: Iaf7755168d662d44c5b3ff72ca93c6cd72425e45
2 files changed