* Set up CI with Azure Pipelines

* Clean up solution structure

* Delete SkyWalking.NetworkProtocol

* remove HostingStartup

* Rename "SkyWalking.AspNetCore" to "SkyWalking.Agent.AspNetCore"

* Add SkyWalking.DotNet.CLI for SkyWalking dotnet global tool

* Fix CI:  DotnetTool does not support target framework lower than netcoreapp2.1.

* Add SkyWalking.DotNet.CLI.Command parser

* Implement the "dotnet sw install" command to install the SkyWalking .NET Core Agent.

* Add SkyWalking additonalDeps

* Generate config file for SkyWalking .NET Core Agent

* Update DirectoryProvider.cs

* Fix : Access to the path is denied in windows

* Fix : Access to the path is denied in windows

* Change tmp directory log

* Fix Information log level

* Rename SkyWalking.DotNet.CLI tool command

* Update README.md

* Fix : An assembly specified in the application dependencies manifest was not found

* Update README.md

* Fix install SkyWalking DotNet CLI