travis: config cleanup
travis: config cleanup

- use container-based infrastructure
- use parallel builds via `make -j 2`
- run `make test` after build
- change email destination to chrono-dev mailing list
- remove extraneous `env`
- reformat yaml file

amelmquist/chrono,dariomangoni/chrono,tjolsen/chrono,andrewseidl/chrono,Bryan-Peterson/chrono,tjolsen/chrono,andrewseidl/chrono,hsu/chrono,amelmquist/chrono,dariomangoni/chrono,projectchrono/chrono,jcmadsen/chrono,jcmadsen/chrono,rserban/chrono,projectchrono/chrono,Bryan-Peterson/chrono,Milad-Rakhsha/chrono,projectchrono/chrono,rserban/chrono,Bryan-Peterson/chrono,Milad-Rakhsha/chrono,hsu/chrono,jcmadsen/chrono,armanpazouki/chrono,hsu/chrono,Milad-Rakhsha/chrono,amelmquist/chrono,Bryan-Peterson/chrono,rserban/chrono,projectchrono/chrono,projectchrono/chrono,tjolsen/chrono,armanpazouki/chrono,dariomangoni/chrono,tjolsen/chrono,jcmadsen/chrono,amelmquist/chrono,jcmadsen/chrono,amelmquist/chrono,rserban/chrono,armanpazouki/chrono,hsu/chrono,amelmquist/chrono,PedroTrujilloV/chrono,PedroTrujilloV/chrono,Milad-Rakhsha/chrono,jcmadsen/chrono,dariomangoni/chrono,PedroTrujilloV/chrono,armanpazouki/chrono,jcmadsen/chrono,PedroTrujilloV/chrono,armanpazouki/chrono,andrewseidl/chrono,Milad-Rakhsha/chrono,armanpazouki/chrono,dariomangoni/chrono,dariomangoni/chrono,Milad-Rakhsha/chrono,PedroTrujilloV/chrono,projectchrono/chrono,rserban/chrono,tjolsen/chrono,andrewseidl/chrono,rserban/chrono,rserban/chrono,Bryan-Peterson/chrono,hsu/chrono,andrewseidl/chrono