support construct v2.10.68 ?

I'm using construct v2.10.68 and would love to try out construct-editor, but currently `construct-editor (0.0.19) depends on construct (2.10.67)`

Would supporting that be as easy as bumping `construct==2.10.67` to either `construct==2.10.68`, or `construct>=2.10.67` in requirements.txt? I can drop a PR if you like.

Thanks so much