After trying upgrading Nuget package and then again uninstalling / reinstalling all went in vain.
Here's a workaround :-
- Open up csproj file in edit mode
- Add following refrences manually
<ItemGroup>
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.3" />
<DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.3" />
</ItemGroup>
Save the changes, reload the project and rebuild. You will find it working.
Now moving to command prompt, pointing to current project directory if you do a command dotnet ef and hit enter, you will start getting command options which ef core supports.
Hope it helps !