md-echo-test fails to build

[dleslie]

On 2f749a4f3547f9f4b06a2413f30d1efe53e526c6:

Basically, building make z80-tools builds sjasm but not z80asm and yet the md-echo-test example demands z80asm.

I compiled on WSL in an x86-64 ubuntu environment.

[andwn]

z80asm started failing to build a while ago and I was unable to properly fix it myself, so I commented out the build instructions. I think what I'll end up doing here is update the example to just include the echoblob.c (I think that's the name) from the echo repo. Unless sjasm can assemble it... but I doubt it.