remove old statistics_api_client

now unused - replaced mock fn with detailed_services too

app/notify_client/statistics_api_client.py

@@ -1,19 +0,0 @@
-from notifications_python_client.base import BaseAPIClient
-
-
-class StatisticsApiClient(BaseAPIClient):
-    def __init__(self, base_url=None, client_id=None, secret=None):
-        super(self.__class__, self).__init__(base_url=base_url or 'base_url',
-                                             client_id=client_id or 'client_id',
-                                             secret=secret or 'secret')
-
-    def init_app(self, app):
-        self.base_url = app.config['API_HOST_NAME']
-        self.client_id = app.config['ADMIN_CLIENT_USER_NAME']
-        self.secret = app.config['ADMIN_CLIENT_SECRET']
-
-    def get_statistics_for_all_services_for_day(self, day):
-        params = {
-            'day': day
-        }
-        return self.get(url='/notifications/statistics', params=params)