use libdigest-sha-perl; use bash
Merge pull request 5
Fix Ubuntu compatibility problems

Specify /bin/bash instead of /bin/sh since it is actually dash.

Use Digest::SHA instead of Digest:SHA1, Digest::SHA1 is obsolete and not available on Ubuntu.
Merge pull request #6 from Robert-Nelson/ubuntu-compat

Fix Ubuntu compatibility problems
Merge remote-tracking branch 'upstream/master'

Conflicts:
	debian/control
	debian/pkg-cacher-sa.postinst