Add .gitattributes file to better simulate a Windows environment

[kellyselden]

Attempting to reproduce ember-codemods/ember-angle-brackets-codemod#160 on Windows CI.

[kellyselden]

Judging by #163, I think the Windows image has regressed somehow.

[rwjblue]

Ya, I think that GitHub added yarn to the system image. They don’t really give a very good insight into the environment changes :/

[rwjblue]

Thanks for fixing CI! Looks like this is passing now.

Can you explain how this better simulates a windows environment though? The tests I added in #141 are not platform dependent (they use various combos of \n and \r\n confirming the endings are preserved).

[rwjblue]

Either way this seems good (and passes), so I'm going to merge...

[kellyselden]

Can you explain how this better simulates a windows environment though?

The only OS specific difference I can think of between this test suite and ember-cli-update's test suite is this file. I remember fiddling with different settings, and this file was the key to get Windows to preserve it's line endings and git to not force everything into \n. It's all kinda black magic though in the end.