add auto publish npm to @next

.travis.yml

@@ -55,3 +55,7 @@ notifications:
 
 after_success:
   - if [ "$TRAVIS_OS_NAME" == "linux" ]; then npm run coverage; fi
+
+deploy:
+  provider: npm
+  api_key: "$NPM_TOKEN"

README.md

@@ -85,6 +85,8 @@ $ node mybot.js
 
 You might be asked for install the `chromedriver`, depends on which platform you are.
 
+Get to know more about NPM at [Wiki](https://github.com/wechaty/wechaty/wiki/NPM)
+
 # API Reference
 
 ## [Wechaty](https://github.com/wechaty/wechaty/wiki/API#class-wechaty)