Update module github.com/google/go-cmp to v0.5.8

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/PuerkitoBio/goquery v1.7.1
 	github.com/PuerkitoBio/purell v0.1.0
 	github.com/PuerkitoBio/urlesc v0.0.0-20170810143723-de5bf2ad4578 // indirect
-	github.com/google/go-cmp v0.5.6
+	github.com/google/go-cmp v0.5.8
 	github.com/google/uuid v1.1.1 // indirect
 	github.com/pborman/uuid v1.2.1
 	github.com/syndtr/goleveldb v0.0.0-20190923125748-758128399b1d