Get the policy.json prior to running tests
try another fix
remove wget in travis
Centralize context creation

Upstream quantum added policy checks into the context __init__. This
causes context creation to require policy.json when creating an admin
context. Move all the context creation into the base class and specify
not having an admin context by default.
Don't double register options, is no bueno
Merge pull request #53 from jkoelker/fix_context_tests

Centralize context creation