move heroku install to before_install

.travis.yml

@@ -3,7 +3,6 @@ dist: trusty
 rvm:
 - 2.4.4
 before_script:
-  - bash etc/ci-setup.sh
   - gem install bundler -v 1.16.2
   - bundle exec rake hatchet:setup_travis
 jobs:
@@ -11,6 +10,7 @@ jobs:
   - stage: Bash linting (shellcheck)
     sudo: false
     before_install:
+    - bash etc/ci-setup.sh
     - wget -c https://goo.gl/ZzKHFv -O - | tar -xvJ -C /tmp/
     - PATH="/tmp/shellcheck-latest:$PATH"
     script: make check