[Chore] Add bullet gem #249 (#281)

* closes #249 add bullet gem

- upgrade gems
- fix the warning in the console
- fix the deprecation message for where not

.circleci/config.yml

@@ -19,6 +19,13 @@ jobs:
     steps:
       - checkout
 
+      - run:
+          name: Configure Bundler
+          command: |
+            echo 'export BUNDLER_VERSION=$(cat Gemfile.lock | tail -1 | tr -d " ")' >> $BASH_ENV
+            source $BASH_ENV
+            gem install bundler
+
       - run:
           name: Which bundler?
           command: bundle -v