Verify staleness of generated code during build

.travis.yml

@@ -18,4 +18,5 @@ install:
   - make deps
 
 script:
+  - hack/verify-codegen.sh
   - travis_wait 20 goveralls -service=travis-ci -package ./pkg/... -v

Makefile

@@ -44,6 +44,7 @@ clean:
 	rm -rf build scm-source.json
 
 local: ${SOURCES}
+	hack/verify-codegen.sh
 	CGO_ENABLED=${CGO_ENABLED} go build -o build/${BINARY} $(LOCAL_BUILD_FLAGS) -ldflags "$(LDFLAGS)" $^
 
 linux: ${SOURCES}