chore(infrastructure): Use JWT addon for SauceLabs CI Tests (#4730)
chore(infrastructure): Use JWT addon for SauceLabs CI Tests (#4730)

TravisCI now supports [JSON Web Tokens](https://docs.travis-ci.com/user/jwt) in order to run Sauce
Labs tests from both external/internal PRs. This commit uses the JWT addon to encrypt
SAUCE_ACCESS_KEY so that our SauceLabs tests will run regardless of where a PR comes from.

Also removes `sudo: required` from our builds, since it does not seem
necessary any more.
material-components/material-components-web,sbrieuc/material-design-lite,Yizhachok/material-components-web,material-components/material-components-web,Yizhachok/material-components-web,pgbross/material-components-web,anton-kachurin/material-components-web,pgbross/material-components-web,sbrieuc/material-design-lite,material-components/material-components-web,anton-kachurin/material-components-web