add wechaty-version util

Dockerfile

@@ -14,7 +14,7 @@ RUN groupadd -r wechaty && useradd -m -r -g wechaty wechaty -d /wechaty
 
 WORKDIR /wechaty
 COPY . .
-RUN npm install
+RUN npm install && npm link
 
 COPY entrypoint.sh /entrypoint.sh
 RUN bash -n /entrypoint.sh && chmod a+x /entrypoint.sh

bin/version.js

+#!/usr/bin/env node
+
+const { Wechaty } = require('..')
+
+const w = new Wechaty()
+console.log(w.version())

entrypoint.sh

@@ -3,7 +3,7 @@
 # Credit: https://github.com/cusspvz/node.docker/blob/master/entrypoint
 #
 
-echo 'Wechaty Docker Starting'
+echo "Docker Starting Wechaty v$(wechaty-version)"
 
 # to identify run env (for tests)
 export WECHATY_DOCKER='docker'

package.json

@@ -22,7 +22,8 @@
     "url": "git+https://github.com/zixia/wechaty.git"
   },
   "bin": {
-    "io-bot": "bin/io-bot.js"
+    "io-bot": "bin/io-bot.js",
+    "wechaty-version": "bin/version.js"
   },
   "keywords": [
     "wechat",