chore(travis): use SauceConnect v4

See https://saucelabs.com/docs/connect
chore(travis): use latest selenium on SL
chore(travis/e2e): update Chrome to v34

See 28ef2637c111d2940d2062c3cc8be29e7984f35a
chore(travis/e2e): use Chrome on Mac

Because of this[1] issue, which is Linux specific, we see very frequent failures.

[1]: https://code.google.com/p/chromedriver/issues/detail?id=467