Package Authentication and Process Updates

• Removes use of obsolete .NET Core SDK releases endpoint
• Dependency updates for packages
• Improve documentation clarity
• Adds NuGet package authentication set-up, documentation in README.md

Deprecate version

Deprecate version

v1.1.0

Export dotnet_root

v1.0.2

Consume new toolkit

v1.0.1

Use dotnet-version (#16)

v1.0.0

V1 (#9)

* Consume new tool-cache

* Fix tests

* V1