[WIP] Updated the driver for the Mink 2.0 API

[stof]

This updates the driver for changes done in https://github.com/Behat/Mink/pull/427

Ref https://github.com/Behat/Mink/issues/415

[aik099]

@stof please update this PR (I guess rebasing will do) so it can be merged automatically at least. Same is true for other Mink 2.x related PR's in other drivers.

[stof]

Well, before merging it, we would have to merge things in Mink first. And I have an idea which could help having a single version of the driver for Mink 1.x and 2.x (thanks to a change in CoreDriver) to make the transition easier (allowing us to make improvements on drivers which would be usable for Mink 1.x as well), but I want to experiment with it.

[stof]

for reference, the Mink PR is now actually at https://github.com/Behat/Mink/pull/542

[aik099]

... allowing us to make improvements on drivers which would be usable for Mink 1.x as well ...

I guess we'll be changing a driver to return xpath instead of NodeElement at all times (as in Mink 2.x) but for Mink 1.x we'll create a layer between driver and mink that will do the wrapping in NodeElement.

[stof]

I guess we'll be changing a driver to return xpath instead of NodeElement at all times (as in Mink 2.x) but for Mink 1.x we'll create a layer between driver and mink that will do the wrapping in NodeElement.

My idea is indeed to implement find in the CoreDriver, with a protected abstract method doing the actual finding returning XPath (the 2.x API), and doing the building of NodeElement in the CoreDriver. This way, any driver using this method instead of implementing find() directly would be compatible with both versions

[stof]

Closing in favor of #123 as the change done in 1.7 means that drivers don't have anything to change for 2.0 anymore