Replace sprockets/browserify with Webpack (#2617)

* Replace browserify with webpack

* Add react-intl-translations-manager

* Do not minify in development, add offline-plugin for ServiceWorker background cache updates

* Adjust tests and dependencies

* Fix production deployments

* Fix tests

* More optimizations

* Improve travis cache for npm stuff

* Re-run travis

* Add back support for custom.scss as before

* Remove offline-plugin and babili

* Fix issue with Immutable.List().unshift(...values) not working as expected

* Make travis load schema instead of running all migrations in sequence

* Fix missing React import in WarningContainer. Optimize rendering performance by using ImmutablePureComponent instead of
React.PureComponent. ImmutablePureComponent uses Immutable.is() to compare props. Replace dynamic callback bindings in
<UI />

* Add react definitions to places that use JSX

* Add Procfile.dev for running rails, webpack and streaming API at the same time

.travis.yml

@@ -1,9 +1,7 @@
 language: ruby
 cache:
   bundler: true
-  yarn: true
-  directories:
-    - node_modules
+  yarn: false
 dist: trusty
 sudo: false
 
@@ -42,7 +40,8 @@ install:
   - yarn install
 
 before_script:
-  - bundle exec rails db:create db:migrate
+  - bundle exec rails db:create db:schema:load
+  - bundle exec rails assets:precompile
 
 script:
   - bundle exec rspec