Implement Audio playback

[craigthomas]

This PR adds audio playback to the emulator. It works by adding an audio_pattern_buffer that is 16 bytes long. The 16 byte pattern is then converted into a 128-bit array, by taking each bit of the pattern and generating either a 0 or a 1. The array is then resampled so that it matches the playback frequency of Pygame's mixer. This PR closes #32

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.87%. Comparing base (1da3918) to head (efb7d63).
Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #41      +/-   ##
==========================================
+ Coverage   90.27%   92.87%   +2.60%     
==========================================
  Files           4        4              
  Lines         473      660     +187     
==========================================
+ Hits          427      613     +186     
- Misses         46       47       +1     

Files	Coverage Δ
chip8/cpu.py	96.45% <100.00%> (-0.89%)	⬇️

... and 1 file with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d73204c...efb7d63. Read the comment docs.