Add webpack-cli and greenkeepr lockfile

.travis.yml

@@ -1,11 +1,13 @@
 language: node_js
 node_js:
-  - 6
   - 8
-  - 9
 script:
   - yarn travis
 
+before_install: yarn global add greenkeeper-lockfile@1
+before_script: greenkeeper-lockfile-update
+after_script: greenkeeper-lockfile-upload
+
 after_success:
   - ./travis-upload-artifacts.sh
 

package.json

@@ -47,6 +47,7 @@
     "lodash-webpack-plugin": "^0.11.4",
     "style-loader": "^0.20.1",
     "webpack": "^3.1.0",
+    "webpack-cli": "^2.0.13",
     "webpack-dev-server": "^2.11.1",
     "webpack-merge": "^4.1.1",
     "webpack-shell-plugin": "^0.5.0"