Change package name to clapp (closes #4)

.reuse/dep5

 Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
-Upstream-Name: exposed
+Upstream-Name: clapp
 Upstream-Contact: Andre Anjos <andre.anjos@idiap.ch>
-Source: https://gitlab.idiap.ch/bob/exposed
+Source: https://gitlab.idiap.ch/software/clapp
 
 Files: tests/data/*
 Copyright: Copyright © 2022 Idiap Research Institute <contact@idiap.ch>