Add glue to backends to support server mode

moto/backends.py

@@ -20,6 +20,7 @@ from moto.elbv2 import elbv2_backends
 from moto.emr import emr_backends
 from moto.events import events_backends
 from moto.glacier import glacier_backends
+from moto.glue import glue_backends
 from moto.iam import iam_backends
 from moto.instance_metadata import instance_metadata_backends
 from moto.kinesis import kinesis_backends
@@ -65,6 +66,7 @@ BACKENDS = {
     'events': events_backends,
     'emr': emr_backends,
     'glacier': glacier_backends,
+    'glue': glue_backends,
     'iam': iam_backends,
     'moto_api': moto_api_backends,
     'instance_metadata': instance_metadata_backends,