Update README.md

Author: bgavrilMS

Diff for: 1-Call-MSGraph/README.md

@@ -47,7 +47,7 @@ For more information on the concepts used in this sample, be sure to read the [M
 
 To run this sample, you'll need:
 
-- [Visual Studio 2017](https://aka.ms/vsdownload) or just the [.NET Core SDK](https://www.microsoft.com/net/learn/get-started)
+- [Visual Studio 2017](https://aka.ms/vsdownload) or newer, or just the [.NET Core SDK](https://www.microsoft.com/net/learn/get-started)
 - An Internet connection
 - A Windows machine (necessary if you want to run the app on Windows)
 - An OS X machine (necessary if you want to run the app on Mac)