Update CircleCI to test first

.circleci/config.yml

@@ -1,6 +1,17 @@
 version: 2
 jobs:
-  build:
+  test:
+    docker:
+      - image: circleci/node:8.11.1
+    steps:
+      - checkout
+      - run:
+          name: Install dependencies
+          command: npm install
+      - run:
+          name: Run tests
+          command: npm test
+  build-latest:
     docker:
       - image: circleci/node:8.11.1
     steps:
@@ -9,3 +20,15 @@ jobs:
       - run: npm install
       - run: npm run build
       - run: bash deploy.sh
+workflows:
+  version: 2
+  build-latest:
+    jobs:
+      - test
+      - build-latest:
+          requires:
+            - test
+          filters:
+            branches:
+              only:
+                - master