Fix config.yml to decrease the concurrency on release

Author: mocchira

.circleci/config.yml

@@ -198,23 +198,26 @@ workflows:
               only: /.*/
       - package-ubuntu14.04:
           requires:
-            - release-base
+            - package-centos6
+            - package-centos7
           filters:
             branches:
               ignore: /.*/
             tags:
               only: /.*/
       - package-ubuntu16.04:
           requires:
-            - release-base
+            - package-centos6
+            - package-centos7
           filters:
             branches:
               ignore: /.*/
             tags:
               only: /.*/
       - package-ubuntu18.04:
           requires:
-            - release-base
+            - package-centos6
+            - package-centos7
           filters:
             branches:
               ignore: /.*/