added missing setup.py which blocks pip install

When trying to install the sssapi using pip you consistently get

```
Obtaining python-sdk from git+https://github.com/snowshoestamp/python_sdk.git#egg=python_sdk
  Updating /Users/rosscdh/.virtualenvs/toolkit/src/python-sdk clone
  Running setup.py egg_info for package python-sdk
    Traceback (most recent call last):
      File "<string>", line 16, in <module>
    IOError: [Errno 2] No such file or directory: '/Users/rosscdh/.virtualenvs/toolkit/src/python-sdk/setup.py'
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):

  File "<string>", line 16, in <module>

IOError: [Errno 2] No such file or directory: '/Users/rosscdh/.virtualenvs/toolkit/src/python-sdk/setup.py'
```

this is caused by the missing setup.py which also defines how python should link in the package.

1. added missing setup.py with some default values (please review the values)
2. you must have this file in order to get the package installed otherwise you need to do what you currently do and describe how to download and unzip a package etc.. gets a bit old.. fast.
3. you also need this file for distribution on pypi which you def want to get devs using your libs