Cy 3.1.0, package lock

Author: bahmutov

.npmrc

@@ -0,0 +1,2 @@
+save-exact=true
+package-lock=true

.travis.yml

@@ -2,13 +2,13 @@ language: node_js
 cache:
   directories:
     - ~/.npm
-    - node_modules
+    - ~/.cache
 notifications:
   email: true
 node_js:
   - '8'
 before_script:
-  - npm prune
+  - npm ci
 script:
   - npm run lint
   - npm test -- --record