Make the CPX Simple Simon compatible with CPB

[Neradoc]

This makes the code for the Circuit Playground Simple Simon compatible with the CPB.
I don't think there is another version of it that already works ?
https://learn.adafruit.com/circuit-playground-simple-simon/code-walk-through

• use cp not cpx from the adafruit_circuitplayground library
• do not read the analog pin A7 (not available on CPB)
• reference cp.touch_TX (available on both) instead of cp.touch_A7

Also:

• fix the call to game_lost() which takes a step and not a sequence[setp]
• use a context manager to setup and deinit the analog pins
• some spaces at the end of lines

[dhalbert]

Looks good, thanks! Does the guide text need updating?

[dhalbert]

Does the guide text need updating?

I updated the guide text: just needed to change the alert that said it only works on CPX.