Added a buildbot for dwz

[Mark Wielaard <mark@klomp.org>]

Hi,

To celebrate that dwz now has a testsuite I added a buildbot:
https://builder.wildebeest.org/buildbot/#/builders?tags=dwz

It monitors the dwz.git master branch and does a make && make check
on every new commit it sees for aarch64, armhf, ppc64, ppc64le, s390x,
x86_64 and i386.

The ppc64 and ppc64le builders currently fail because they
don't have dejagnu installed yet. As soon as that is installed
I expect those to also become green.

It should sent email to this list when a new failure is detected.

Cheers,

Mark