Add bundle size github workflow (#2005)

* Add bundle size github workflow

This workflow implements a bundle-size monitoring utility for our repository to give better metrics on increases in bundle-sizes. I basically copied the configuration for the WordPress gutenberg project workflow and it utilizes the [`preactjs/compressed-size-action`](https://github.com/preactjs/compressed-size-action).

If this works well, it will replace our existing bundlesize implementation.

* remove bundlewatch and related scripts

* more lint job fixes

- remove build:ci because it was only used for bundlesize check. No need to build files for linting checks.
- add lint:ci npm script for doing build lint checks
- update travis job config to use new script and update title

* change name of workflow

.github/workflows/bundle-size.yml

@@ -0,0 +1,16 @@
+name: Bundle Size
+
+on: [pull_request]
+
+jobs:
+    build-and-size:
+        runs-on: ubuntu-latest
+
+        steps:
+            - uses: actions/checkout@v2-beta
+              with:
+                  fetch-depth: 1
+            - uses: preactjs/compressed-size-action@v1
+              with:
+                  repo-token: '${{ secrets.GITHUB_TOKEN }}'
+                  pattern: '{build/**/*.js,build/**/*.css}'

.travis.yml

@@ -70,10 +70,10 @@ jobs:
               - npm run test
           env:
               - WOOCOMMERCE_BLOCKS_PHASE=experimental
-        - name: Javascript/CSS Lint and Bundle Size Check
+        - name: Javascript/CSS Lint check
           script:
               - npm install
-              - npm run build:ci
+              - npm run lint:ci
           env:
               - WOOCOMMERCE_BLOCKS_PHASE=experimental
         - name: E2E Tests