Add mongodb and imap tests for dal

Added mongodb uri string for tests

gluon/tests/__init__.py

@@ -3,7 +3,9 @@ import os, sys
 from test_http import *
 from test_cache import *
 
-if "google" in (os.getenv("DB") or []):
+NOSQL = any([name in (os.getenv("DB") or "")
+             for name in ("datastore", "mongodb", "imap")])
+if NOSQL:
     from test_dal_nosql import *
 else:
     from test_dal import *