Issue 2181

[glagnar]

Resolve issue 2181, and update PetStore example.
It does seem though, that the PetStore had more changes than I expected.

[wing328]

@glagnar thanks for the PR. The test cases passed for me

Test Case '-[SwaggerClientTests.UserAPITests testLogout]' started.
Test Case '-[SwaggerClientTests.UserAPITests testLogout]' passed (0.728 seconds).
Test Suite 'UserAPITests' passed at 2016-03-02 15:33:15.729.
     Executed 5 tests, with 0 failures (0 unexpected) in 5.022 (5.025) seconds
Test Suite 'SwaggerClientTests.xctest' passed at 2016-03-02 15:33:15.730.
     Executed 11 tests, with 0 failures (0 unexpected) in 12.239 (12.248) seconds
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 02:18 min
[INFO] Finished at: 2016-03-02T15:33:15+08:00
[INFO] Final Memory: 12M/310M
[INFO] ------------------------------------------------------------------------

[wing328]

FYI. For #2181