Added statsd integration into the API

- new client for statsd, follows conventions used elsewhere for configuration
- client wraps underlying library so we can use a config property to send/not send statsd

Added statsd metrics for:
- count of API successful calls SMS/Email
- count of successful task execution for SMS/Email
- count of errors from Client libraries
- timing of API calls to third party clients
- timing of how long messages live on the SQS queue

app/clients/sms/loadtesting.py

@@ -11,8 +11,9 @@ class LoadtestingClient(FiretextClient):
     Loadtest sms client.
     '''
 
-    def init_app(self, config, *args, **kwargs):
+    def init_app(self, config, statsd_client, *args, **kwargs):
         super(FiretextClient, self).__init__(*args, **kwargs)
         self.api_key = config.config.get('LOADTESTING_API_KEY')
         self.from_number = config.config.get('LOADTESTING_NUMBER')
         self.name = 'loadtesting'
+        self.statsd_client = statsd_client