update: update version to 1.7.2

Author: LynnL4

platform.txt

@@ -20,7 +20,7 @@
 # https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5---3rd-party-Hardware-specification
 
 name=Seeed SAMD (32-bits ARM Cortex-M0+ and Cortex-M4) Boards
-version=1.6.1
+version=1.7.2
 
 # Compile variables
 # -----------------