Support installing the latest patch or minor version

TL;DR

Support a version format of 2.1.x or 2.x and the latest patch or minor version of .NET Core will be installed.

Summary

It’s quite a common pattern to be able to omit a minor or patch version and tooling will get the latest version.

For instance Azure Pipeline Use .NET V2 Task provides this mechanism.

This will allow a build matrix like this to be specified:

jobs:
  build:
    runs-on: ubuntu-16.04
    strategy:
      matrix:
        dotnet: [ '2.1', '2.2', '3.0' ]
    name: Dotnet ${{ matrix.dotnet }} sample
    steps:
      - uses: actions/checkout@master
      - name: Setup dotnet
        uses: actions/setup-dotnet@v1
        with:
          dotnet-version: ${{ matrix.dotnet }}
      - run: dotnet build <my project>

The following options would be useful

• 2 or 2.x or 2.* - Installs the latest version of .NET Core 2, currently 2.2.401
• 2.1 or 2.1.x or 2.1.* - Installs the latest version of .NET Core 2.1, currently 2.1.801

[Fronix]

Any progress here, tests are kind of halted right now since 3.1.201 doesn’t seem to work at all.

[JSkimming]

@rainersigwald, my opinion is that’s a risk the consumer take on, as long as it’s explicit. Maybe a warning in the output to make it more prominent?

I don’t use the 2.x wildcard as I know the SDK may not be compatible between minor versions, but I do use the 2.2.x wildcard a lot, and while I have occasionally found breaking changes, they were considered bugs.