Describe your environment.
I'm using Python 3.8 and because of some performance changes in Flask 2, I will need to use it, even if it's an RC version. Namely Flask==2.0.0rc1. Now, the problem is that opencensus-ext-flask has a dependency on Flask with version < 2. This is not a bug per se, nor a feature, but it would be nice to have opencensus-ext-flask see Flask 2 as a valid dependency, without us having to clone it and change that dependency

Steps to reproduce.
Install Flask==2.0.0rc1 and opencensus-ext-flask==0.7.4

What is the expected behavior?
Having them installed and working.

What is the actual behavior?

The conflict is caused by:
     opencensus-ext-flask 0.7.4 depends on flask<2.0.0 and >=0.12.3