iOS群聊文档
Merge branch 'master' of https://github.com/easemob/developer.easemob.com

# By Strong Liu (10) and others
# Via eastrain
* 'master' of https://github.com/easemob/developer.easemob.com:
  update groupchat
  添加静态库40多M的说明
  test github trigger
  test github trigger
  test github trigger
  add rvmrc
  add rvmrc
  update docs
  update docs
  update docs
  update docs format
  update docs
  update
  update group doc
  update singlechat
  整理文档