Merge pull request #188 from KoenZomers/patch-1

Modified readme to express that Wix 3.x needs to be used as it has a reference to that folder specifically. Wix 4.x will not work.

README.md

@@ -9,7 +9,7 @@ This solution shows how you can build a library of PowerShell commands that act
 -  SharePoint 2013 on-premises
 
 ### Prerequisites ###
-In order to build the setup project the WiX toolset needs to be installed. You can obtain this from http://wix.codeplex.com. If you use Visual Studio 2015 you will need at least WiX 3.10, which can be downloaded from here: http://wixtoolset.org/releases/
+In order to build the setup project the WiX toolset needs to be installed. You can obtain this from http://wix.codeplex.com. If you use Visual Studio 2015 you will need at least WiX 3.10, but do not install WiX v4.x, which can be downloaded from here: http://wixtoolset.org/releases/
 
 In order to generate the Cmdlet help you need Windows Management Framework v4.0 which you can download from http://www.microsoft.com/en-us/download/details.aspx?id=40855