fix manifest to include CHANGELOG.rst not CHANGELOG.txt
fix manifest to include CHANGELOG.rst not CHANGELOG.txt

futurice/slumber,infoxchange/slumber,IAlwaysBeCoding/slumber,zongxiao/slumber,jannon/slumber,ministryofjustice/slumber,s-block/slumber,CloudNcodeInc/slumber,samgiles/slumber,IAlwaysBeCoding/More