add cmd/open_im_msg_gateway

cmd/open_im_msg_gateway/Makefile

@@ -0,0 +1,26 @@
+.PHONY: all build run gotool install clean help
+
+BINARY_NAME=open_im_msg_gateway
+BIN_DIR=../../bin/
+LAN_FILE=.go
+GO_FILE:=${BINARY_NAME}${LAN_FILE}
+
+all: gotool build
+
+build:
+	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-w -s" -o  ${BINARY_NAME}  ${GO_FILE}
+
+run:
+	@go run ./
+
+gotool:
+	go fmt ./
+	go vet ./
+
+install:
+	make build
+	mv ${BINARY_NAME} ${BIN_DIR}
+
+clean:
+	@if [ -f ${BINARY_NAME} ] ; then rm ${BINARY_NAME} ; fi
+