chore: re-enable bundlesize check (#2382)

Author: Alan Shaw

.travis.yml

@@ -25,7 +25,7 @@ jobs:
   include:
     - stage: check
       script:
-        # - npx aegir build --bundlesize
+        - npx aegir build --bundlesize
         - npx aegir dep-check -- -i wrtc -i electron-webrtc
         - npm run lint