Fix npm lock file name

Enforce npm package version from package.json

.gitignore

@@ -1,6 +1,6 @@
 node_modules
 yarn.lock
-npm.lock
+package-lock.json
 /tmp
 *.log
 ~*

package.json

@@ -9,9 +9,9 @@
     "build": "npm run build:cleancss && npm run build:pp && npm run build:uglify && npm run build:bookmarklet && npm run build:apache-cdn && npm run build:apache-local"
   },
   "devDependencies": {
-    "clean-css": "^4.2.1",
-    "clean-css-cli": "^4.2.1",
+    "clean-css": "4.2.1",
+    "clean-css-cli": "4.2.1",
     "preprocessor": "1.4.0",
-    "uglify-js": "^3.4.9"
+    "uglify-js": "3.4.9"
   }
 }