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

tests/javascripts/jest.config.js

@@ -18,7 +18,7 @@ module.exports = {
     url: 'https://beta.notify.gov',
   },
   transform: {
-    '^.+\\.js$': 'babel-jest',
+    '^.+\\.js$': ['babel-jest', { rootMode: 'upward' }],
   },
   transformIgnorePatterns: [
     'node_modules/(?!(d3|d3-array|d3-axis|d3-brush|d3-chord|d3-collection|d3-color|d3-contour|d3-dispatch|d3-drag|d3-dsv|d3-ease|d3-fetch|d3-force|d3-format|d3-geo|d3-hierarchy|d3-interpolate|d3-path|d3-polygon|d3-quadtree|d3-random|d3-scale|d3-scale-chromatic|d3-selection|d3-shape|d3-tile|d3-time|d3-time-format|d3-timer|d3-transition|d3-voronoi|d3-zoom)/)'