Rename driver 'activate' method to 'create'.

This will change the driver API to be more in-line with the
'hpcs_action' states.

libra/worker/controller.py

@@ -89,10 +89,10 @@ class LBaaSController(object):
                 lb_node['condition'] = self.NODE_OK
 
         try:
-            self.driver.activate()
+            self.driver.create()
         except NotImplementedError:
             self.logger.error(
-                "Selected driver does not support activating changes."
+                "Selected driver does not support CREATE action."
             )
             for lb_node in self.msg['nodes']:
                 lb_node['condition'] = self.NODE_ERR

libra/worker/drivers/base.py

@@ -38,8 +38,8 @@ class LoadBalancerDriver(object):
         """ Add a server for which we will proxy. """
         raise NotImplementedError()
 
-    def activate(self):
-        """ Activate any changes made. """
+    def create(self):
+        """ Create the load balancer. """
         raise NotImplementedError()
 
     def suspend(self):

libra/worker/drivers/haproxy/driver.py

@@ -116,6 +116,6 @@ class HAProxyDriver(LoadBalancerDriver):
             self._config['servers'] = []
         self._config['servers'].append((host, port))
 
-    def activate(self):
+    def create(self):
         self._write_config()
         self._restart()