Ensure package-wide test init is done with testr

This patch adds testresources.ResourcedTestCase as another base class
for compute and boto tests. This allows us to perform package-wide
init for tests when running them under testr. The init was not being
performed when the tests were run under testr because setup_package is
a nosetests specific init feature. The setup_package functions in
__init__.py files are renamed to ensure that the initialisation is
only done once.

Implements: blueprint speed-up-tempest
Change-Id: If76f71cb06f2243607db2680504e94dc65e1f585
diff --git a/tempest/tests/compute/__init__.py b/tempest/tests/compute/__init__.py
index 190cb5f..a00ec77 100644
--- a/tempest/tests/compute/__init__.py
+++ b/tempest/tests/compute/__init__.py
@@ -37,7 +37,7 @@
 
 
 # All compute tests -- single setup function
-def setup_package():
+def generic_setup_package():
     LOG.debug("Entering tempest.tests.compute.setup_package")
 
     global MULTI_USER, DISK_CONFIG_ENABLED, FLAVOR_EXTRA_DATA_ENABLED