[master] Update dependencies from 3 repositories (#12198)

* Update dependencies from https://github.com/aspnet/AspNetCore-Tooling build 20190715.2
- Microsoft.NET.Sdk.Razor - 3.0.0-preview8.19365.2
- Microsoft.CodeAnalysis.Razor - 3.0.0-preview8.19365.2
- Microsoft.AspNetCore.Razor.Language - 3.0.0-preview8.19365.2
- Microsoft.AspNetCore.Mvc.Razor.Extensions - 3.0.0-preview8.19365.2

* Update dependencies from https://github.com/dotnet/arcade build 20190715.4
- Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19365.4
- Microsoft.DotNet.GenAPI - 1.0.0-beta.19365.4
- Microsoft.DotNet.Helix.Sdk - 2.0.0-beta.19365.4

* Update dependencies from https://github.com/aspnet/EntityFrameworkCore build 20190715.5
- Microsoft.EntityFrameworkCore.Tools - 3.0.0-preview8.19365.5
- Microsoft.EntityFrameworkCore.SqlServer - 3.0.0-preview8.19365.5
- dotnet-ef - 3.0.0-preview8.19365.5
- Microsoft.EntityFrameworkCore - 3.0.0-preview8.19365.5
- Microsoft.EntityFrameworkCore.InMemory - 3.0.0-preview8.19365.5
- Microsoft.EntityFrameworkCore.Relational - 3.0.0-preview8.19365.5
- Microsoft.EntityFrameworkCore.Sqlite - 3.0.0-preview8.19365.5