When installing from the source distribution (for packaging or other
purposes), it's convenient to be able to install the bash completion
file as part of that process.
In order to validate installation it's very convenient to have the tests
as part of the source distribution. This greatly assists native
packaging that might occur (i.e. Gentoo ebuilds).
Signed-off-by: Alex Brandt <alunduil@alunduil.com>