Fix golint path - it moved upstream

build/Dockerfile

@@ -52,7 +52,7 @@ RUN curl -fsSLo shfmt https://github.com/mvdan/sh/releases/download/v1.3.0/shfmt
 RUN go get \
     github.com/weaveworks/build-tools/cover \
     github.com/mattn/goveralls \
-	github.com/golang/lint/golint \
+	golang.org/x/lint/golint \
 	github.com/fzipp/gocyclo \
 	github.com/fatih/hclfmt \
 	github.com/client9/misspell/cmd/misspell