Add unit tests

platformio.ini

@@ -56,6 +56,7 @@ build_unflags =
 
 [env:lolin_s3_mini_qr]
 extends = env:lolin_s3_mini
+test_framework = unity
 build_flags =
     ${env:lolin_s3_mini.build_flags}
     -D USE_QR
@@ -64,6 +65,7 @@ build_flags =
 extends = btclock_base
 board = btclock
 board_build.partitions = partition_16mb.csv
+test_framework = unity
 build_flags =
     ${btclock_base.build_flags}
     -D MCP_INT_PIN=4