Bring in correct config for toolkit integration

From
https://github.com/alphagov/govuk_elements/commit/a1eb5af4d9ac9e8df47cc000f6ad7ba6115f256c

Removes the govuk/public/node_modules folder which
was included as a mistake.
Bump govuk_frontend_toolkit to 0.46.1

Includes new files & new compilation results.
Give alpha banner new markup pattern

Styles for new pattern were added here:

https://github.com/alphagov/govuk_frontend_toolkit/commit/5bedef8ea363830b2c0665c01c9ce783e563ee22
Merge pull request #13 from tombye/add-new-banner-and-toolkit

Add new banner and toolkit