Plugin Treats package-name and package.name as not equal

[mdlopresti]

Pip treats packages where there is a dash in the name and packages with a '.' in the name as equivalent. I've run into this on some of our internal packages but an example from a public package is pydoc-markdown==4.6.3

Expected behaviour

Should find all dependencies when running snyk code

Actual behaviour

Throws 'Required packages missing: nr.util' error even thou nr-util is installed.

Steps to reproduce

Create a requirements.txt file with the contents of 'pydoc-markdown==4.6.3'
Run pip install -r requirements
Run snyk test