Added circleci tests.

.circleci/config.yml

@@ -0,0 +1,16 @@
+jobs:
+  build_and_test: # this can be any name you choose
+    executor: node/default # use the default executor defined within the orb
+    steps:
+      - checkout
+      - node/install-packages:
+          pkg-manager: yarn
+      - run:
+          command: yarn test
+          name: Run tests
+      - run:
+          command: yarn build
+          name: Build app
+      - persist_to_workspace:
+          root: ~/
+          paths: .