Remove dogstatsd-python in favor of dogapi

Also added datadog application to commom django apps and set it to use
a local statsd server by default.

cms/envs/aws.py

@@ -147,7 +147,12 @@ MODULESTORE = AUTH_TOKENS['MODULESTORE']
 CONTENTSTORE = AUTH_TOKENS['CONTENTSTORE']
 
 # Datadog for events!
-DATADOG_API = AUTH_TOKENS.get("DATADOG_API")
+DATADOG = AUTH_TOKENS.get("DATADOG", {})
+DATADOG = DATADOG.update(ENV_TOKENS.get("DATADOG", {}))
+
+# TODO: deprecated (compatibility with previous settings)
+if 'DATADOG_API' in AUTH_TOKENS:
+    DATADOG['api_key'] = AUTH_TOKENS['DATADOG_API']
 
 # Celery Broker
 CELERY_BROKER_TRANSPORT = ENV_TOKENS.get("CELERY_BROKER_TRANSPORT", "")

cms/envs/common.py

@@ -358,6 +358,9 @@ INSTALLED_APPS = (
     # Tracking
     'track',
 
+    # Monitoring
+    'datadog',
+
     # For asset pipelining
     'mitxmako',
     'pipeline',