Get standalone server mode working for all tests.

moto/instance_metadata/urls.py

@@ -0,0 +1,12 @@
+from __future__ import unicode_literals
+from .responses import InstanceMetadataResponse
+
+url_bases = [
+    "http://169.254.169.254"
+]
+
+instance_metadata = InstanceMetadataResponse()
+
+url_paths = {
+    '{0}/(?P<path>.+)': instance_metadata.metadata_response,
+}