Verify network connectivity before state check

This commit adds an initial ssh connection after bringing a server up
in setUp. This should ensure that the image has a chance to initialize
prior to messing with it's state. The test's here are to verify that
after performing a nova operation on a running instance network
connectivity is retained. However, it's is never checked that we can
connect to the server in the first place. A probable cause for the
constant ssh failures in these tests is that the server hasn't had a
finish it's cloud-init (or cirros-init) stage when we're stopping it,
this should also fix those issues.

Change-Id: I126fd4943582c4b759b3cc5a67babaa8d062fb4d
Partial-Bug: #1349617
diff --git a/tempest/scenario/test_network_advanced_server_ops.py b/tempest/scenario/test_network_advanced_server_ops.py
index 431de9a..2850b1b 100644
--- a/tempest/scenario/test_network_advanced_server_ops.py
+++ b/tempest/scenario/test_network_advanced_server_ops.py
@@ -73,6 +73,9 @@
                                          create_kwargs=create_kwargs)
         self.floating_ip = self._create_floating_ip(self.server,
                                                     public_network_id)
+        # Verify that we can indeed connect to the server before we mess with
+        # it's state
+        self._wait_server_status_and_check_network_connectivity()
 
     def _check_network_connectivity(self, should_connect=True):
         username = CONF.compute.image_ssh_user