:construction_worker: ignore gh-pages branch in CircleCI

.circleci/config.yml

diff --git a/.circleci/config.yml b/.circleci/config.yml
index b39f06a..0d7a847 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -44,11 +44,11 @@
   version: 2
   build_and_test_all:
     jobs:
-      - build_stable
+      - build_stable:
           branches:
             ignore:
               gh-pages
-      - build_bleeding_edge
+      - build_bleeding_edge:
           branches:
             ignore:
               gh-pages