chore: use npm ci

.appveyor.yml

@@ -26,10 +26,11 @@ install:
   # install node
   # Get the latest stable version of Node.js or io.js
   - ps: Install-Product node $env:nodejs_version
+  - npm i -g npm@latest
   # install grunt-cli globally
   - npm install -g grunt-cli
   # install modules
-  - npm install
+  - npm ci
 
 test_script:
   # Output useful info for debugging

.travis.yml

@@ -5,8 +5,12 @@ node_js:
   - "10"
 
 before_install:
+  - npm i -g npm@latest
   - npm install -g grunt-cli
 
+install:
+  - npm ci
+
 # travis build  speed up
 sudo: false
 cache: