Add contributor credits in ChangeLog

ChangeLog

@@ -2,21 +2,32 @@ version 1.0.3 -- UNRELEASED
 
     backupninja changes
 	 · Add validation check for when parameter
+	   Thanks to ulrich <ulrich@habmalnefrage.de> for the patch
 	 · Quote output strings passed to logging functions
 	 · Ignore files in /etc/backup.d that lack suffix
+	   Thanks to David Gasaway <dave@gasaway.org> for the patch
+	 · Add Vagrantfile to help with testing/release process
     documentation changes
 	 · Fix typos in README.md and manpages. Thank you, Lintian!
 	 · Improve release process documentation
     handler changes
 	borg:
-	 . Add initial support
-	dub:
+	 . Add initial support for the borgbackup program
+	   Thanks to Ben <ben@wainei.net> and Thomas Preissler
+	   <thomas@preissler.co.uk> for contributing patches
+	dup:
 	 · Fix symmetric encryption
+	   Thanks to Matthijs Wensveen <matthijs.wensveen@gmail.com> for
+	   the patch.
 	 · Bail if archive dir doesn't exist
+	   Thanks to Hugh Nowlan <nosmo@nosmo.me> for the patch
 	sys:
 	 · Use lsblk instead of sfdisk to get a list of block devices
+	   Thanks to Romain Dessort <romain@univers-libre.net> for the patch
 	 · Avoid looking for partitions on zram devices
+	   Thanks to Glandos <bugs-0xacab@antipoul.fr> for the patch
 	 · Support extracting LUKS headers from partitions
+	   Thanks to Lyz <lyz@riseup.net> for the patch. 
 
 version 1.0.2 -- September 05, 2017
     handler changes