Use GCS env vars in testing environment

Author: naglepuff

tox.ini

@@ -15,8 +15,10 @@ deps =
 setenv =
   NMDC_ENVIRONMENT = testing
   SQLALCHEMY_SILENCE_UBER_WARNING=1
+  NMDC_GCS_USE_FAKE = true
 passenv =
   NMDC_TESTING_DATABASE_URI
+  NMDC_GCS_FAKE_API_ENDPOINT
 commands =
     nmdc-server generate-static-files --remove-existing
     nmdc-server storage init