Dependencies declaration fix and Framework update

[MissaouiChedy]

Hi @volkovku ,

Recently I installed the RazorTemplate NuGet package on a project and I had to add the Razor Engine dependency manually, furthermore after cloning the RazorTemplate repository and opening the project in visual studio I had again add some dependencies manually.

I believe I added the correct dependency declarations, and I updated as well the target framework for all projects to .Net 4.6.

So now the NuGet package for RazorTemplate should be installed with the correct dependencies and restoring the visual studio solution should install all the needed libraries.

I am looking forward for your feedback. Kind regards, Chedy.