Use safe_setup instead try block in setUpClass

To avoid resource leakage in case of exception in setUpClass,
some tests have try catch block in setUpClass and call tearDownClass
explicitly.
safe_setup decorator is for same purpose which should be
used instead.

Change-Id: I59372ec96dcec0058d30e503b22540ce09c43d43
Fix TypeError in TestVolumeBootPattern

Commit eef192fc3c98a663f99f2fd944611bce0adffc0c changed
self._log_console_output() to self._log_console_output(self)
when dumping an instance's console output when ssh fails.

self in this case is the test class which is not an instance
(or list for that matter) so it blows up when we hit this
patch and masks the root failure.

Change-Id: Ieb68503a43269997a36c0a8b7f19f78ace97f251
Closes-Bug: #1363552
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
Merge "Fix TypeError in TestVolumeBootPattern"
Merge "Use safe_setup instead try block in setUpClass"
Merge "Verify network connectivity before state check"
Merge branch 'master' of https://github.com/openstack/tempest