Update OrleansTestingHost.csproj

Fix ToolVersion=12

Merge pull request dotnet#444 from sergeybykov/1.0.8

Uniformity of NuGet packages versions and bump up to 1.0.8.

OrleansVSTools.vsix with a code-signed OrleansVSTools.dll.

v1.0.3 Release of NuGets with Azure Storage dependency bumped to 4.2