Test PCF8574 chips with leds

Dependencies:   mbed PCF8574

Revision:
0:759957225002
diff -r 000000000000 -r 759957225002 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Mon Jul 22 01:29:04 2019 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/mbed_official/code/mbed/builds/65be27845400
\ No newline at end of file