Skip amphora scenario test if provider is not set

This patch also removes py27 and py35 from list of envs in tox. We don't
have functional tests.

Change-Id: Id9255fe87d61bf6536c8d03f9dd7612abc451904

octavia_tempest_plugin/tests/scenario/v2/test_amphora.py

@@ -30,6 +30,15 @@ CONF = config.CONF
 class AmphoraScenarioTest(test_base.LoadBalancerBaseTest):
     """Test the amphora object API."""
 
+    @classmethod
+    def skip_checks(cls):
+        super(AmphoraScenarioTest, cls).skip_checks()
+
+        if CONF.load_balancer.provider not in ['amphora', 'octavia']:
+            raise cls.skipException("Amphora tests require provider 'amphora' "
+                                    "or 'octavia' (alias to 'amphora', "
+                                    " deprecated) set")
+
     @classmethod
     def resource_setup(cls):
         """Setup resources needed by the tests."""

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 2.0
-envlist = py35,py27,pep8
+envlist = pep8
 skipsdist = True
 
 [testenv]