Add support for Python 3

[amotl]

Hi again,

I believe we should get the code up to speed, add support for Python 3 and drop support for Python 2, which is way past end-of-life already.

With kind regards,
Andreas.

[insipiens]

When working on the my docker version of audiohealth these are the modules I used:

environment: Debian Buster/Python 3.8

sudo apt-get -y install make python3-aubio aubio-tools build-essential sox libsox-fmt-all xvfb xauth youtube-dl

Python modules (from pip freeze):

cycler==0.11.0
docopt==0.6.2
fonttools==4.29.1
kiwisolver==1.3.2
matplotlib==3.5.1
numpy==1.17.4
packaging==21.3
paho-mqtt==1.6.1
Pillow==9.0.1
pyparsing==3.0.7
python-dateutil==2.8.2
scipy==1.3.3
six==1.16.0

I found Aubio needed installing last & separately possibly due to its age/dependencies(?):

python -m pip install aubio

This above needs verifying as it has not been taken from a clean python environment (apologies).

regards
John

[amotl]

Thanks for sharing those detailed instructions!