I had no support for Visual Studio 2015 in my first beta. I fixed this and added a pester test script to test the init.ps1.
I also notices that there are problems with older versions of SharePoint on premises. Therefor I created a second nuget package. The original package SPOEmulators now uses the dependent package Microsoft.SharePointOnline.CSOM as the source for the CSOM assemblies (version 16). The new package SPOEmulators (on-premises) directly references the version 15 of the CSOM assemblies.
For details how to use the SPOEmulators refer to the readme on github.com or to my original post here.