make a proper python package

we want to make our program easy to install:
```
pip install surelock
```

or like:
```
git clone https://github.com/xorond/surelock
cd surelock
./setup.py install
```

we need to write a setup.py script to do this for us, or make a python pip pkg. idk which one is easier in terms of publishing & long term maintenance/sustainability.