Add NOTICE-generator

Author: bkcsoft

.drone.yml

@@ -16,6 +16,7 @@ pipeline:
     commands:
       - apk -U add openssh-client
       - make clean
+      - make notice-up-to-date
       - make generate
       - make vet
       - make lint

Makefile

@@ -63,6 +63,14 @@ errcheck:
 	fi
 	errcheck $(PACKAGES)
 
+NOTICE: vendor/
+	rm -f NOTICE # `govendor license` appends...
+	govendor license -o NOTICE +v
+
+notice-up-to-date: NOTICE
+	git ls-files --error-unmatch NOTICE
+	git diff --exit-code
+
 .PHONY: lint
 lint:
 	@hash golint > /dev/null 2>&1; if [ $$? -ne 0 ]; then \