Add logging filter for checking that the app is actually deployed

(imported from commit 77bd7e008fdea4033e18a91d206999f9714e0f74)

zephyr/lib/logging_util.py

@@ -45,3 +45,8 @@ class EmailLimiter(_RateLimitFilter):
 class ReturnTrue(logging.Filter):
     def filter(self, record):
         return True
+
+class RequireReallyDeployed(logging.Filter):
+    def filter(self, record):
+        from django.conf import settings
+        return settings.DEPLOYED and not settings.TESTING_DEPLOYED