Enable pretendToBeVisual by default

[just-boris]

This flag enables requestAnimationFrame method, which is a requirement for running React in the testing environment.

Currently I need to do the following:

require('global-jsdom')(undefined, { pretendToBeVisual: true });

It would be great to make global-jsdom/register doing this by default.

[modosc]

thanks for the issue - i'm torn about changing this behavior by default since there'd be no easy way to opt out.

otoh - it would be nice for some variation of import 'global-jsdom/register / -r global-jsdom/register to support this out of the box. maybe a new entry point global-jsdom/register-visual ? i have to rethink the register code anyway due to #84 so i'll churn on this too.

[modosc]

i realized i'm already setting some default options and making a major release with breaking changes so i went ahead and added this in too. i just published 8.0.0.beta2 with this change.

[just-boris]

Very nice, thank you!