add arm build target

Makefile

-.PHONY: build clean tool lint help
+.PHONY: arm build clean tool lint help
 
 check=$(shell if [ ! -d "./build/" ]; then mkdir build; else echo "exist"; fi;)
 version=$(shell ./version.sh) 
 tarfile = $(shell echo "chain33-pai_$(version).tar.gz" | sed s/[[:space:]]//g)
 all: build
 
+arm:
+	@GOOS=linux GOARCH=arm GOARM=7 go build -v -o pai .
+	@echo $(check)
+	@rm -rf chain33-pai
+	@mkdir chain33-pai
+	@mv pai chain33-pai/chain33-pai
+	@cp *.sh chain33-pai
+	@cp -r conf chain33-pai
+	@cp -r scripts chain33-pai
+	@chmod +x chain33-pai/*.sh
+	@chmod +x chain33-pai/scripts/*.sh
+	@tar cvfpz $(tarfile) chain33-pai
+	@mv $(tarfile) build
+	@rm -rf chain33-pai
+	@echo "ok"
+
 build:
 	@go build -v -o pai .
 	@echo $(check)