Improve Makefile to include an indirect dependency

Change-Id: I9c062d4d7fdb9496ecc41ca385f53f1da94e82f2
diff --git a/Makefile.PL b/Makefile.PL
index 02bc475..b18c6f6 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -27,7 +27,8 @@
     'IO::Dir::Recursive' => 0.03,
     'File::Temp'      => 0,
     'Directory::Iterator' => 0,
-    'Dumbbench'       => '0.111',
+    'Module::Install' => 1.19,
+    'Dumbbench'       => 0.501,
     'Benchmark'       => 0,
     'Unicode::Normalize' => 0,
     'Carp'            => 0,