Switch to using automatic keystone v2/v3 version detection
using new amulet charmhelpers in functional tests.
Enable xenial/queens amulet test as part of extended tests.
Change-Id: I4de220d3561bf065a3f1f64455cda22a7a807c1a
Depends-On: Ie6e2733f34de10a4d34b18dbf1fd9ba623af0e18
Depends-On: Ibcc36ca22d72d310921f840e6081608be1fbc7e1