Get rid of FastLED

[LaszloAshinFormlabs]

FastLED emits warnings already.
When we upgrade to esp8266 platform 3.0.0 it will emit a lot of new warnings as well and cause LED flickering.
Maybe a new version of FastLED will solve this but the code doesn't seem to be very portable.

Also FastLED doesn't support using esp8266's I2S capability -- but that would also need some change in the wiring.

#29 (comment)

@petamas @balintfodor @PeterVarhegyiF thoughts?

• Do you think we can change the wiring? LED strip data input should go to NodeMCU's RX instead of D2 (still needs to be tested, I am asking theoretically)
• Do you agree we should drop FastLED?