Gherkin cypress spike (#673)

* integrate gherkin/cucumber w/ cypress

- change cypress.json config from e2e back to standard integration
- add cypress-cucumber-preprocessor
- add integration test of about page

* add a title to each page

* add intl to the 404 page

* Refactor explore tool page

- add intl to static strings
- replace component css with <Grid> layout

* Add title to contact page

* add intl to title of page

* Add gherkin tests for nav to about page

- navigate from any page to the about page
- ensure each link has the title correct on that page

client/cypress/integration/LegacyTests/constants.js

@@ -0,0 +1,6 @@
+export const ENDPOINTS = {
+  ABOUT: 'en',
+  EXPLORE_THE_TOOL: '/en/cejst',
+  METHODOLOGY: '/en/methodology',
+  CONTACT: 'en/contact',
+};