Run CI with both latest and frozen dependencies

Author: Obi-Dann

.travis.yml

@@ -1,6 +1,13 @@
 language: node_js
+
 node_js:
   - "10"
+
 branches:
   only:
     - master
+
+jobs:
+  include:
+    - install: npm ci
+    - install: npm install --no-shrinkwrap