added travis-ci status to REAME
added travis-ci status to REAME

ojacobson/dryad-repo,rnathanday/dryad-repo,ojacobson/dryad-repo,rnathanday/dryad-repo,jimallman/dryad-repo,jimallman/dryad-repo,ojacobson/dryad-repo,jimallman/dryad-repo,rnathanday/dryad-repo,rnathanday/dryad-repo,jimallman/dryad-repo,jimallman/dryad-repo,ojacobson/dryad-repo,rnathanday/dryad-repo,ojacobson/dryad-repo,jimallman/dryad-repo,rnathanday/dryad-repo,ojacobson/dryad-repo