Revert "upgrade prometheus client_golang to v1.2.1" (cloudfoundry#557)

* Revert "Merge pull request cloudfoundry#552 from qibobo/dev_qy_upgrade_prometheusgo"

This reverts commit 12d173b, reversing
changes made to bc8e77c.

* Revert "upgrade prometheus client_golang to v1.2.1"

This reverts commit 994eab5.

.gitmodules

@@ -148,9 +148,6 @@
 [submodule "src/github.com/juju/ratelimit"]
 	path = src/github.com/juju/ratelimit
 	url = https://github.com/juju/ratelimit
-[submodule "src/github.com/cespare/xxhash"]
-	path = src/github.com/cespare/xxhash
-	url = https://github.com/cespare/xxhash.git
 [submodule "src/github.com/jmoiron/sqlx"]
 	path = src/github.com/jmoiron/sqlx
-	url = https://github.com/jmoiron/sqlx
+	url = https://github.com/jmoiron/sqlx

src/autoscaler/healthendpoint/registrar.go

@@ -10,12 +10,7 @@ import (
 func RegisterCollectors(registrar prometheus.Registerer, collectors []prometheus.Collector, includeDefault bool, logger lager.Logger) {
 
 	if includeDefault {
-		err := registrar.Register(prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{
-			PidFn: func() (int, error) {
-				return os.Getpid(), nil
-			},
-			Namespace: "",
-		}))
+		err := registrar.Register(prometheus.NewProcessCollector(os.Getpid(), ""))
 		if err != nil {
 			logger.Error("Failed to register process collector", err)
 		}