Revert "temporarily disable most CI checks"

This reverts commit 1193824.

Author: philippotto

.circleci/not-on-master.sh

@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
 set -Eeuo pipefail
 
-# if [ "${CIRCLE_BRANCH}" == "master" ]; then
+if [ "${CIRCLE_BRANCH}" == "master" ]; then
   echo "Skipping this step on master..."
-# else
-#   exec "$@"
-# fi
+else
+  exec "$@"
+fi