Run Cypress tests on Travis CI with Mountebank stubs

.travis.yml

@@ -2,10 +2,34 @@ language: node_js
 node_js:
   - 12.2.0
 
-script:
-  - npm run compile
-  - npm run lint
-  - npm test -- --forbid-only --forbid-pending
+addons:
+  apt:
+    packages:
+      # Ubuntu 16+ does not install this dependency by default, so we need to install it ourselves
+      - libgconf-2-4
 
+cache:
+  # Caches $HOME/.npm when npm ci is default script command
+  # Caches node_modules in all other cases
+  npm: true
+  directories:
+    # we also need to cache folder with Cypress binary
+    - ~/.cache
 
+install:
+  - npm ci
 
+jobs:
+  include:
+    - stage: "Tests"
+      name: "Lint & Test"
+      script:
+        - npm run compile
+        - npm run lint
+        - npm test -- --forbid-only --forbid-pending
+    - script:
+        - npm run cypress:server > /dev/null 2>&1 &
+        - sleep 3
+        - npm run cypress:test
+      name: "Cypress Tests"
+