add promlinter to lint metrics name

Signed-off-by: Ben Ye <[email protected]>

Author: yeya24

go.mod

@@ -56,6 +56,7 @@ require (
 	github.com/ultraware/whitespace v0.0.4
 	github.com/uudashr/gocognit v1.0.1
 	github.com/valyala/quicktemplate v1.5.1
+	github.com/yeya24/promlinter v0.0.0-20200723202054-8a669871391e
 	golang.org/x/tools v0.0.0-20200710042808-f1c4188a97a1
 	gopkg.in/yaml.v2 v2.3.0
 	honnef.co/go/tools v0.0.1-2020.1.4