chore: Bundle Stats / Webpack v4 (#1448)

* chore: Experiment with bundle size monitoring service

* chore: Ensure build runs on CI, move lint and flow before test

* chore: Upgrade Webpack v3 -> v4

* chore: Add webpack-cli
Remove unused dep
Move deps to dev

* Move babel deps to production

* Move babel deps to production

.circleci/config.yml

@@ -29,12 +29,15 @@ jobs:
       - run:
           name: migrate
           command: ./node_modules/.bin/sequelize db:migrate --url $DATABASE_URL_TEST
-      - run:
-          name: test
-          command: yarn test
       - run:
           name: lint
           command: yarn lint
       - run:
           name: flow
-          command: yarn flow check --max-workers 4
+          command: yarn flow check --max-workers 4
+      - run:
+          name: test
+          command: yarn test
+      - run:
+          name: build
+          command: yarn build