@matt-lethargic, I have raised this PR to fix existing issues

Hi @SpartaDeveloper93 thanks for the PR. What issues is this fixing?

@matt-lethargic , I was looking for a GeoJSON library to use in our application and stumbled upon this project. I saw that the last build failed, so I forked the repo.
When running the test cases locally, I noticed that one of the test cases is failing in the main branch: Can_DeserializeGeneric . It was not working and couldn't capture anything in features array
I made the change in "Feature Collection" as that one had an Inconsistent modifier declaration.
Also, TestProperties needs to be lowercase for JSON to deserialize to work. The other solution can be to actually add "JsonPropertyName" there which will work too, not sure which one would you prefer.
Also, changed csproj to just removed net462 and add netstandard 2.0 to make it consistent with main project.

Thanks