Exclude tests package from installation.

Installing the top-level tests package is asking for conflicts with
other python packages and isn't required to run fig.  This simply lets
find_packages know to ignore tests and any sub-packages.
Merge pull request #397 from alunduil/master

Exclude tests package from installation.
Validate DCO on Travis

Copied straight from Docker, replacing github.com/docker/docker
with github.com/docker/fig in .validate.

Signed-off-by: Ben Firshman <ben@firshman.co.uk>
Merge pull request #404 from bfirsh/validate-dco

Validate DCO on Travis
Add a new fig command for retrieving the locally bound port of a service.

Signed-off-by: Daniel Nephin <dnephin@gmail.com>