initial implmentation for support keystone V3
keystone v3 support

- create token
- list projects
updated tests
factor out version extraction
updated tests
Merge branch 'feature/keystonev3' into feature/refactor/keystone

Conflicts:
	lib/aviator/core/service.rb
	lib/aviator/core/session.rb
	lib/aviator/core/session_data.rb
	lib/aviator/openstack/common/v3/public/base.rb
	test/support/request_helper.rb