Asp.net 5.0 MVC6 EF6 Migration Scripts
If you want to use EF6 with ASP.NET MVC6, then expose EF6 repositories as Web API 2 in .NET 4.5 and consume them in ASP.NET MVC6.
I know its lots of additional work, I followed this approach to learn and develop MVC6 applications because of existing EF6 data access layer and similar issues in EF6 to EF7 migrations.
Have you tried this: http://www.bricelam.net/2014/09/14/migrations-on-k.html ?It's for EF 7, but I think you could just change the version to EF6.