Add `generate` as the prerequisite for make build

Change-Id: Idfbc782fddaafc8dd0ee7c4b9b946bd4869e3644
Signed-off-by: Taewan Kim <t25.kim@samsung.com>
diff --git a/Makefile b/Makefile
index e5ed63d..7c05b0c 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,7 @@
 #   limitations under the License.
 #
 
-build:
+build: generate
 	go build -o ricdms cmd/ric-dms.go
 
 generate:
@@ -32,4 +32,4 @@
 docker-run:
 	docker run -it --rm -d -p 8000:8000 ric-dms:v1.0
 
-all: generate build test image
\ No newline at end of file
+all: generate build test image