File missing in amplitude analysis sound example

[bmoren]

Nature of issue?

• Found a bug

Details about the bug:

File missing in amplitude analysis sound example:
https://editor.p5js.org/p5/sketches/S1EgmNgJXuQ

the file assets/lucky_dragons_-_power_melody.mp3 does not exist and causes the editor to crash when the sketch is run.

• Web browser and version:

Firefox 64.0.2
Google Chrome | 72.0.3626.96 (Official Build) (64-bit)

• Operating System:
  os X 10.13.4

• Steps to reproduce this bug:

try to run the amplitude analysis sound example

[catarak]

thanks for reporting! i'm pretty sure this is due to the sunsetting of rawgit. also reported in #820.