pio: fix deprecated flag

Author: cujomalainey

platformio.ini

@@ -29,7 +29,7 @@ board = teensy31
 
 [env:native]
 platform = native
-test_build_project_src = true
+test_build_src = true
 build_flags = -Wno-c++11-extensions -std=c++11
 
 [env:huzzah32]
@@ -40,6 +40,10 @@ board = featheresp32
 [env:nrf52_express]
 board = adafruit_feather_nrf52840_s340
 framework = arduino
-platform = nordicnrf52
-platform_packages = framework-arduinoadafruitnrf52 @ https://github.com/cujomalainey/Adafruit_nRF52_Arduino
+platform = https://github.com/cujomalainey/platform-nordicnrf52.git#develop
 ; upload_protocol = jlink
+
+[env:seeed_xiao]
+platform = https://github.com/maxgerhardt/platform-nordicnrf52
+board = xiaoblesense
+framework = arduino