Add Rancher provider again

vendor/github.com/rancher/go-rancher-metadata/metadata/utils.go

@@ -0,0 +1,19 @@
+package metadata
+
+import (
+	"time"
+)
+
+func testConnection(mdClient Client) error {
+	var err error
+	maxTime := 20 * time.Second
+
+	for i := 1 * time.Second; i < maxTime; i *= time.Duration(2) {
+		if _, err = mdClient.GetVersion(); err != nil {
+			time.Sleep(i)
+		} else {
+			return nil
+		}
+	}
+	return err
+}