in Python 2.7, list_platform() shows some module variables

[hupili]

Try list_platform() in snscli.

Output:

Supported platforms:
   * Email
   * FacebookFeed
   * RSS
   * RSS2RW
   * RSSSummary
   * RenrenBlog
   * RenrenFeed
   * RenrenPhoto
   * RenrenShare
   * RenrenStatus
   * RenrenStatusDirect
   * SQLite
   * SinaWeiboBase
   * SinaWeiboStatus
   * SinaWeiboWapStatus
   * TencentWeiboStatus
   * TwitterStatus
   * fpath
   * i

Python version,

$python
Python 2.7 (r27:82500, Sep 16 2010, 18:02:00) 
[GCC 4.5.1 20100907 (Red Hat 4.5.1-3)] on linux2

[hupili]

snsapi/plugin_trial/__init__.py introduced extra variables. @fqj1994