Merge pull request #390 from intercom/as/0903-circle2.0

Migrate to Circle2.0

Author: askibola

.circleci/config.yml

@@ -0,0 +1,12 @@
+version: 2
+jobs:
+  build:
+    docker:
+      - image: circleci/ruby:2.3.7
+
+    working_directory: ~/intercom-ruby
+
+    steps:
+      - checkout
+      - run: bundle install
+      - run: bundle exec rake