Reauth didn't close old connection

which cause file descriptor leaks
diff --git a/provider_client.go b/provider_client.go
index d920913..e813e0e 100644
--- a/provider_client.go
+++ b/provider_client.go
@@ -192,6 +192,7 @@
 			if options.RawBody != nil {
 				options.RawBody.Seek(0, 0)
 			}
+			resp.Body.Close()
 			resp, err = client.Request(method, url, options)
 			if err != nil {
 				return nil, fmt.Errorf("Successfully re-authenticated, but got error executing request: %s", err)