requirements.txt missing from source 0.8.0 distribution in pypi

The `requirements.txt` file is missing from the source distribution 0.8.0 in pypi:

```
$ python setup.py build
Traceback (most recent call last):
  File "setup.py", line 17, in <module>
    with open("./requirements.txt") as f:
IOError: [Errno 2] No such file or directory: './requirements.txt'
```