[WIP] Added dao method and rest endpoint for getting template

statistics by service.

Some cosmetic changes to imports.

Added fix for job rest not correctly returning errors.

app/template_statistics/rest.py

@@ -0,0 +1,36 @@
+from flask import (
+    Blueprint,
+    jsonify,
+    request,
+    current_app
+)
+
+from app.dao.notifications_dao import dao_get_template_statistics_for_service
+
+from app.schemas import template_statistics_schema
+
+template_statistics = Blueprint('template-statistics',
+                                __name__,
+                                url_prefix='/service/<service_id>/template-statistics')
+
+from app.errors import register_errors
+
+register_errors(template_statistics)
+
+
+@template_statistics.route('')
+def get_template_statistics_for_service(service_id):
+    if request.args.get('limit_days'):
+        try:
+            limit_days = int(request.args['limit_days'])
+        except ValueError as e:
+            error = 'Limit days {} is not an integer'.format(request.args['limit_days'])
+            current_app.logger.error(error)
+            return jsonify(result="error", message=[error]), 400
+    else:
+        limit_days = None
+    stats = dao_get_template_statistics_for_service(service_id, limit_days=limit_days)
+    data, errors = template_statistics_schema.dump(stats, many=True)
+    if errors:
+        return jsonify(result="error", message=errors), 400
+    return jsonify(data=data)