Make compatible with .Net Core 2.0 and .Net Standard 2.0
In order for Envers to work in CoreFX with SQL Server, a preview version of System.Data.SqlClient 4.5.0 must be used. My sense is it's more of an NHibernate thing than an Envers thing.
Also, tests for TransactionScope needed to be ignored under Core because System.Transactions is not supported in Core. At least not yet.