Match project and solution files to same version of visual studio

[rajan-chari]

Currently the solution file (rl.sln) use VS2017 and the project files and toolset are VS2015. Need to keep them consistent.
a) Upgrade all projects to VS2017 -or- b) Downgrade solution file to VS2015 -or- c) Provide VS2015 compatible solution file and a VS2017 compatible solution file.

[jackgerrits]

I would say the best option is to upgrade to VS2017 since the C# project files are only compatible with VS2017+

[lokitoth]

Are you sure the project files and solution are not targeting the same thing? (The reason it says "Visual Studio 2015" on the projects when loading the solution is that we are using the vc140 toolchain, which I believe uses the VS2015 project system.

[jackgerrits]

The solution has been removed so this is no longer an issue.