code format: remove trailing whitespace
fixed missing requirements lib
using nosetests as runtests.sh's test command
add "Contributing" in README.md
change ignore rule order
Fixed issuse #2 files with protocol error

* git@github.com:yourname/workin.git
* 无该问题

```
$ git --version
git version 1.9.1
```
Merge pull request #3 from akun/master

完善参与开发的相关说明和依赖问题
Merge pull request #4 from akun/bugfix/#2

Fixed issuse #2 files with protocol error