Update cloud.google.com version

Author: Jim Kalafut

go.mod

@@ -3,10 +3,10 @@ module github.com/google/go-metrics-stackdriver
 go 1.12
 
 require (
-	cloud.google.com/go v0.37.2
+	cloud.google.com/go v0.37.4
 	github.com/armon/go-metrics v0.0.0-20190430140413-ec5e00d3c878
 	github.com/golang/protobuf v1.3.1
-	google.golang.org/api v0.3.0
+	google.golang.org/api v0.3.1
 	google.golang.org/genproto v0.0.0-20190404172233-64821d5d2107
 	google.golang.org/grpc v1.19.0
 )