tko: Add a Makefile to help with protobuf compilation

So it's easier, more convenient to compile the protocol
buffer python serialization parser that is automatically
generated.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
job_serializer_unittest: Build the protocol buffer serializer

Before importing the serializer, try to build it. It
will all work if you have installed the google protocol
buffers compiler, which you can do on Fedora doing:

sudo yum install protobuf-compiler

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
frontend.pkgdeps: Add protocol buffer compiler

So you can execute the tko serializer unittests.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>