Updated clients to have a more robust error handling

- fire text and omg much more similar. Ready to be combined.
- Error handling now for JSON valid responses

app/clients/sms/loadtesting.py

@@ -1,4 +1,7 @@
 import logging
+
+from flask import current_app
+
 from app.clients.sms.firetext import (
     FiretextClient
 )
@@ -13,7 +16,9 @@ class LoadtestingClient(FiretextClient):
 
     def init_app(self, config, statsd_client, *args, **kwargs):
         super(FiretextClient, self).__init__(*args, **kwargs)
+        self.current_app = current_app
         self.api_key = config.config.get('LOADTESTING_API_KEY')
         self.from_number = config.config.get('LOADTESTING_NUMBER')
         self.name = 'loadtesting'
+        self.url = "https://www.firetext.co.uk/api/sendsms/json"
         self.statsd_client = statsd_client