Project updated to target both .net framework and .netstandard

[eaton-sam]

Updated prismicio.csproj to new project format. Now targets .net framework 4.5 (as it did before) as well as .net standard 2.0. Updated Newtonsoft.Json to a version which supports both of these.

Had to add NUnitTestAdapter to prismicio.test.csproj so that test runner works in VS 2019.
4 FragmentTests are failing, as they currently are on the main branch.

This allows for use of this package in anything that supports .net standard, such as .net core and mono. Microsoft recommends all new projects use .net core rather than .net framework.

Thanks

[benembery]

@eaton-sam I've been working with the folks at prismic on a new version of the prismicio package for .net core. It has some differences to this kit which are covered in the very simple sample in the repo.
https://github.com/adaptivewebworks/prismicio-netstandard-kit

[eaton-sam]

@eaton-sam I've been working with the folks at prismic on a new version of the prismicio package for .net core. It has some differences to this kit which are covered in the very simple sample in the repo.
https://github.com/adaptivewebworks/prismicio-netstandard-kit

Ahh that's great, thanks. I completely missed that when searching the nuget feed in VS, there's a few different packages knocking around now. Might be worth adding a package description and source link to your nuget package.

As for this pull request, is this repo essentially abandoned?
The changes I made mean the library functions as it did for 4.5, just also target netstandard. Is it worth merging anyway or not?

[benembery]

I've adandonded a similar PR a while back too, based on the feedback from prismic team.
I'm not sure whether they are maintaining features for the this library or not.
I'll update the package description and source link as soon as I can.