Fix Makefile.

Author: brocaar

interface/Makefile

@@ -1,4 +1,4 @@
-.PHONY: api
+.PHONY: api ui
 
 PROTOC_PATH := ./ui/node_modules/grpc-tools/bin/protoc
 PROTOC_ARGS := -I=./api --js_out=import_style=commonjs:./api/grpc-web --grpc-web_out=import_style=commonjs+dts,mode=grpcwebtext:./api/grpc-web/
@@ -10,4 +10,4 @@ api:
 	$(PROTOC_PATH) $(PROTOC_ARGS) api/api.proto
 
 ui:
-	cd ui && yarn add file:./api/grpc-web && yarn install && yarn build
+	cd ui && yarn add file:../api/grpc-web && yarn install && yarn build