Adding the new fields for template stats.

Signed-off-by: Cliff Hill <Clifford.hill@gsa.gov>

app/template_statistics/rest.py

@@ -23,7 +23,7 @@ def get_template_statistics_for_service_by_day(service_id):
     try:
         whole_days = int(whole_days)
     except ValueError:
-        error = "{} is not an integer".format(whole_days)
+        error = f"{whole_days} is not an integer"
         message = {"whole_days": [error]}
         raise InvalidRequest(message, status_code=400)