dependencies for running piuparts slave from git

 piuparts is meant as a quality assurance tool for people who create .deb
 packages to test them before they upload them to the Debian package archive.
 A master/slave piuparts installation is used for testing complete archives
 as it is done on https://piuparts.debian.org/.
 .
 This metapackage provides all the dependencies needed for running a
 piuparts-slave instance from git.