Reduce parameters to base class execute

Simplify the parameters so we are just passing a command string
to the execute command in the base class.  The string is exactly
the command we are going to run.  This will make debugging
easier and make it clearer what we are actually running.

Change-Id: I0425007e1849f31d692420e38544c55b1acb86c4

Author: TerryHowe

functional/common/test.py

@@ -26,10 +26,8 @@
 EXAMPLE_DIR = os.path.join(ROOT_DIR, 'examples')
 
 
-def execute(cmd, action, flags='', params='', fail_ok=False,
-            merge_stderr=False):
+def execute(cmd, fail_ok=False, merge_stderr=False):
     """Executes specified command for the given action."""
-    cmd = ' '.join([cmd, flags, action, params])
     cmd = shlex.split(cmd.encode('utf-8'))
     result = ''
     result_err = ''
@@ -47,9 +45,10 @@ class TestCase(testtools.TestCase):
 
     delimiter_line = re.compile('^\+\-[\+\-]+\-\+$')
 
-    def openstack(self, action, flags='', params='', fail_ok=False):
+    @classmethod
+    def openstack(cls, cmd, fail_ok=False):
         """Executes openstackclient command for the given action."""
-        return execute('openstack', action, flags, params, fail_ok)
+        return execute('openstack ' + cmd, fail_ok=fail_ok)
 
     def assert_table_structure(self, items, field_names):
         """Verify that all items have keys listed in field_names."""