runtime: Windows installer should warn about missing required updated

Steps to reproduce

1. Provision/find/etc. a machine running Windows Server 2008 R2 Server Core and DO NOT apply updates.
2. Install the Windows x64 Installer from https://github.com/dotnet/cli/blob/rel/1.0.0/README.md
3. Upon completion, run “C:\Program Files\dotnet\dotnet.exe --help”

Expected behavior

The install should warn or block because the required hotfix KB2533623 has not been installed

Actual behavior

The install succeeds and attempts to invoke dotnet.exe result in:

Failed to load the dll from [C:\Program Files\dotnet\host\fxr\1.0.1\hostfxr.dll], HRESULT: 0x80070057

Environment data

dotnet --info output:

Failed to load the dll from [C:\Program Files\dotnet\host\fxr\1.0.1\hostfxr.dll], HRESULT: 0x80070057

ver output:

Microsoft Windows [Version 6.1.7601]