why not setup one dedicated conda env for fastai-0.7 and another for fastai-1.0.x, then it should work just fine. you just conda activate envname1, test, conda activate envname2, test, done. (probably will need to restart jupyter but may be not)
I don’t know if we have a docker, I wasn’t here at the time of fastai-0.7, perhaps someone created one - search the forums? e.g. I found this one Docker for fast.ai I don’t know whether it’s still working. But I think the first paragraph of this post should give you what you need.
if you’re on windows you will need to follow these instructions Howto: installation on Windows