Removed statsd from the api and use the statsd in the utils library.

The statsd code was added to the utils library a while ago, uses the
statsd from the util library and therefore consolidates the code into
once place.

app/dao/inbound_sms_dao.py

@@ -3,12 +3,12 @@ from datetime import (
     datetime
 )
 from flask import current_app
+from notifications_utils.statsd_decorators import statsd
 from sqlalchemy import desc
 
 from app import db
 from app.dao.dao_utils import transactional
 from app.models import InboundSms
-from app.statsd_decorators import statsd
 
 
 @transactional