Added batch processing class for documents

Change-Id: I91ab289ffff525978fce3079a4dad71caddfe98a
diff --git a/Makefile.PL b/Makefile.PL
index b4bdacb..1ab8172 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -22,6 +22,7 @@
     'List::MoreUtils' => 0.33,
     'Parallel::ForkManager' => 1.17,
     'IO::Compress::Gzip' => 2.069,
+    'IO::Uncompress::Gunzip' => 2.069,
     'IO::Dir::Recursive' => 0.03,
     'File::Temp'      => 0,
     'Directory::Iterator' => 0,