Can't enable migrations for Entity Framework on VS 2017 .NET Core

I just installed VS 2017 and created a new Core project. Inside it, I added:

• Microsoft.EntityFrameworkCore (1.1.0)
• Microsoft.NETCore.App (1.1.0)

I also created a folder called Models with a class in it. Then, I went to the Package Manager Console and executed enable-migrations so that VS will create the files needed for me. However, instead of the needed files, I got the following error.

The term 'enable-migration' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.

What am I supposed to do here?

I seem to be out of luck googling. It's a very unusual combination (Core VS17 and EF) so there's virtually no info on the subject. Some guides talk about editing package.json by hand which is kind of hard because VS 2017 seems to upgrade the Core so that dotnet restore doesn't look for it but rather for a xxx.csproj.

In summary, I'm confused and quite uncertain how to bite the problem.