Merge pull request #2743 from daspecster/change-version-specifier-for-core

Set core version compatible specifier to packages.

Author: daspecster

packages/google-cloud-bigtable/setup.py

@@ -50,7 +50,7 @@
 
 
 REQUIREMENTS = [
-    'google-cloud-core >= 0.21.0',
+    'google-cloud-core >= 0.21.0, < 0.22dev',
     'grpcio >= 1.0.0, < 2.0dev',
 ]