Add test case for reused token

git-svn-id: https://plugins.svn.wordpress.org/google-authenticator-per-user-prompt/trunk@903290 b8457f37-d9ea-0310-8a92-e5e31aec5664
Declare create_login_nonce() and verify_login_nonce() as protected.


git-svn-id: https://plugins.svn.wordpress.org/google-authenticator-per-user-prompt/trunk@903293 b8457f37-d9ea-0310-8a92-e5e31aec5664