IOS 2.1.0
Merge branch 'master' of https://github.com/easemob/www.easemob.com

# By Lynch (8) and others
# Via Lynch
* 'master' of https://github.com/easemob/www.easemob.com: (23 commits)
  add mile case
  update images of qingguo and paopao
  speedstat: update js version referrence
  add speedstat target: qing-guangzhou, qing-beijing2
  update
  update
  update download times
  update andorid singchat
  update android doc
  update android doc
  SDK82 1,2
  ui bug
  add casess
  minor fix
  add speedtest target: qq-guangzhou, ali-beijing
  add files for speedstat
  mark rest api high light
  update android doc
  update android doc
  add net speedstat
  ...

Conflicts:
	content/sdk/index.md