Switch to chrome headless instead of phantomjs

[aiomaster]

I noticed a lot of random fails in the feature tests (on travis they were just executed up to 3 times until they hopefully work). Maybe you should consider to use selenium with a real browser like chromium. phantomjs is abondoned and has a very old rendering engine, so it would really be cool to update the test suite to chrome headless and maybe get rid of some of the random failing tests.

[bricesanchez]

Hi @aiomaster,

You're right, we should use another solution, could you provide us a PR ?

:)

[bricesanchez]

@aiomaster I've created a PR for this feature

[aiomaster]

Impressive, thanks a lot!