Like 6a7576a but in javascript

package.json

@@ -27,9 +27,7 @@
     "through2": "^2.0.1"
   },
   "scripts": {
-    "client:version": "cd packages/plug-auth-client && npm version",
-    "server:version": "cd packages/plug-auth-server && npm version",
-    "preversion": "sh ./version.sh",
+    "postversion": "node version.js",
     "prepublish": "npm run install-packages && npm run build",
     "client:install": "cd packages/plug-auth-client && npm install",
     "server:install": "cd packages/plug-auth-server && npm install",

version.js

@@ -0,0 +1,13 @@
+const fs = require('fs')
+const join = require('path').join
+const version = require('./package.json').version
+
+function bump(name, version) {
+  const path = join(__dirname, 'packages', name, 'package.json')
+  const pkg = JSON.parse(fs.readFileSync(path, 'utf8'))
+  pkg.version = version
+  fs.writeFileSync(path, JSON.stringify(pkg, null, 2) + '\n', 'utf8')
+}
+
+bump('plug-auth-client', version)
+bump('plug-auth-server', version)