ci: Ignore main file in licenseok

Makefile

@@ -15,7 +15,7 @@ build:
 	cp ./release/dep-$(PLATFORM)-$(ARCH) dep
 
 licenseok:
-	go build ./hack/licenseok
+	go build -o licenseok ./hack/licenseok/main.go
 
 validate: build licenseok
 	./hack/lint.bash

hack/licenseok/main.go

@@ -1,3 +1,5 @@
+// +build ignore
+
 // Copyright 2017 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

hack/validate-licence.bash

@@ -7,6 +7,6 @@
 # source files to check licence
 set -e
 
-go build ./hack/licenseok
+go build -o licenseok ./hack/licenseok/main.go
 find . -path ./vendor -prune -o -regex ".+\.pb\.go$" -prune -o -type f -regex ".*\.\(go\|proto\)$"\
  -printf '%P\n' | xargs ./licenseok