Feat/webpack (#2998)

* First commit

* Removed govuk for webpack. Modernized javascript importing. Removed dead js

* Fixed tests, a few styling bugs

* Fixed some table errors and regenerated backstop ref images

* Updated tests for coverage

* Changes from carlo suggestions

gulpfile.js

@@ -28,7 +28,6 @@ const javascripts = () => {
     paths.src + 'javascripts/errorBanner.js',
     paths.src + 'javascripts/notifyModal.js',
     paths.src + 'javascripts/date.js',
-    paths.src + 'javascripts/loginAlert.js',
     paths.src + 'javascripts/sidenav.js',
     paths.src + 'javascripts/validation.js',
     paths.src + 'javascripts/scrollPosition.js',