Require either `streamlit` OR `streamlit-nightly` to avoid conflicts

[arturadib]

If I install streamlit-ace with streamlit-nightly already installed, it'll install streamlit which causes issues with the nightly version:

$ pip list | grep streamlit
streamlit-nightly             0.70.1.dev20201101

$ pip install streamlit-ace

$ pip list | grep streamlit
streamlit                     0.71.0
streamlit-ace                 0.0.4
streamlit-nightly             0.70.1.dev20201101

[okld]

Hello @arturadib, I've indeed encountered that issue myself, but I'm not sure how to conditionnally ignore to install streamlit if streamlit-nightly is already installed. Environment markers or extras_require doesn't seem to help here.

And this issue would be common to every other streamlit components.