LED light updates

[crcastle]

LED should follow the following sequence during Arduino boot:

• Solid green for 500ms when power is turned on
• Flashing yellow while booting, connecting to wifi, and making /hello request
  • Flashing red if wifi does not associate with an AP
  • Alternating red and yellow if /hello request returns != 200
  • Solid green if /hello request returns 200

On card scan:

• Solid yellow if card is scanned successfully and GET request made to server
  • Back to solid green if no response is received from server within 5 seconds
  • Solid red for 500ms if non-200 response is received from server (and make bad sound)
  • Solid blue if 200 response received from server (and open solenoid)
• Back to solid green if no flow for > 5 seconds (and close solenoid)