fix: always use dataclasses 0.6 (googleapis#481)

busunkim96 · web-flow · commit 066d04e7d533 · 2020-06-23T10:26:17.000-07:00
diff --git a/requirements.txt b/requirements.txt
@@ -6,4 +6,4 @@ MarkupSafe==1.1.1
 protobuf==3.12.2
 pypandoc==1.5
 PyYAML==5.3.1
-dataclasses==0.6; python_version < '3.7'
+dataclasses==0.6  # TODO(busunkim) remove when 3.6 support is dropped
