Add .gitkeep

package.json

@@ -6,8 +6,9 @@
   "private": true,
   "scripts": {
     "build": "bin/build-checks.js && better-npm-run build",
+    "build-locales": "bin/build-locales",
     "extract-locales": "better-npm-run extract-locales",
-    "clean": "rimraf './dist/*!(.gitkeep)' './webpack-assets.json'",
+    "clean": "rimraf './dist/*!(.gitkeep)' './webpack-assets.json' './src/locale/**(!.gitkeep)'",
     "dev:admin": "better-npm-run dev:admin",
     "dev:amo": "better-npm-run dev:amo",
     "dev:amo:no-proxy": "better-npm-run dev:amo:no-proxy",
@@ -23,11 +24,11 @@
     "unittest:server": "bin/config-check.js && better-npm-run unittest:server",
     "unittest:run": "bin/config-check.js && better-npm-run unittest:run",
     "version-check": "node bin/version-check.js",
-    "webpack-dev-server": "better-npm-run webpack-dev-server"
+    "webpack-dev-server": "npm run build-locales && better-npm-run webpack-dev-server"
   },
   "betterScripts": {
     "build": {
-      "command": "npm run clean && npm run version-check && webpack --bail --verbose --display-error-details --progress --colors --config webpack.prod.config.babel.js",
+      "command": "npm run clean && npm run version-check && npm run build-locales && webpack --bail --verbose --display-error-details --progress --colors --config webpack.prod.config.babel.js",
       "env": {
         "NODE_PATH": "./:./src"
       }