Updating to make net 5.0 work

[renemadsen]

• Adding fixes to make it work with net 5.0.
• Adding build on github actions for Ubuntu and Windows.
• Removing support for net4.5.
• Updating dependencies to latest versions.
• Updating appveyor.yml to run tests.

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Rebus is MIT-licensed. The code submitted in this pull request needs to carry the MIT license too. By leaving this text in, I hereby acknowledge that the code submitted in the pull request has the MIT license and can be merged with the Rebus codebase.

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✅ renemadsen
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[mookid8000]

Hi again @renemadsen , I really appreciate this! But is there any chance you could squash your commits? I'd like to avoid incorporating commits from @dependabot-preview because it's not a human... 😁

Btw. I there's a thing I've been wondering about: I see you added .NET Standard 2.0, .NET Standard 2.1, and .NET 5.0 as build targets.

What is the purpose of .NET Standard 2.1 in this case? Wouldn't you say that packages that aren't capable of leveraging .NET Standard 2.1 stuff (Span<T>, IAsyncEnumerable, ...) should target .NET Standard 2.0 (for broadest possible reach) .. and what is the purpose of targeting .NET 5.0 even? If I understand things correctly, using the .NET 5.0 runtime would bring performance improvements about, even when the code running is .NET Standard 2.0... do you know anything about this?

[renemadsen]

Hi again @renemadsen , I really appreciate this! But is there any chance you could squash your commits? I'd like to avoid incorporating commits from @dependabot-preview because it's not a human...

Yes, I can do that, but do consider using dependabot on your projects, since it makes the life of keeping projects up to date so much easier, when you have a lot of repositories to maintain and it's only updating dependencies.

Btw. I there's a thing I've been wondering about: I see you added .NET Standard 2.0, .NET Standard 2.1, and .NET 5.0 as build targets.

What is the purpose of .NET Standard 2.1 in this case? Wouldn't you say that packages that aren't capable of leveraging .NET Standard 2.1 stuff (Span<T>, IAsyncEnumerable, ...) should target .NET Standard 2.0 (for broadest possible reach) .. and what is the purpose of targeting .NET 5.0 even? If I understand things correctly, using the .NET 5.0 runtime would bring performance improvements about, even when the code running is .NET Standard 2.0... do you know anything about this?

I'll do some testing in that regard, since I actually don't really know.
So probably you are right about setting it to netstandard2.0 would be enough.