Prefix avr-size so it works on platforms without avr-size in the path

Makefile

@@ -5,6 +5,7 @@ BOARD    = model01
 MCU 		= atmega32u4
 
 DEVICE_PORT :=  `ls /dev/cu.usbmodemHID??`
+DEVICE_PORT :=  `ls /dev/cu.usbmodem14?1`
 DEVICE_PORT_BOOTLOADER := `ls /dev/cu.usbmodem14?1`
 ARDUINO_LIBS = 
 GIT_VERSION := $(shell git describe --abbrev=4 --dirty --always)
@@ -58,7 +59,7 @@ compile: dirs
 	cp $(BUILD_PATH)/$(SKETCH).elf $(ELF_FILE_PATH)
 
 size: compile
-	avr-size -C --mcu=$(MCU) $(ELF_FILE_PATH)
+	$(ARDUINO_TOOLS_PATH)/avr/bin/avr-size -C --mcu=$(MCU) $(ELF_FILE_PATH)
 
 reset-device: 
 	stty -f $(DEVICE_PORT) 1200 ;