title: EF Core Update-Database command creates schema for user instead of using dbo
body: <p>I have created a <code>DbContext</code> using EF Core 2.0 and already applied a lot of migrations in the development environment using <code>Update-Database</code> in PM-Console.
  The tables are created using the <code>dbo</code>schema on my localDb as expected and as I know from EF6.</p>
  
  <p>However, when i apply the <code>Update-Database</code> command to my production database on a MSSQL Server, it creates a schema named <code>Domain\Username</code> (my user from my machine). When I then run the server application with its designated domain account, it can not access the database. As a workaround I talked the IT infrastructure guys into allowing this account to execute software on my computer and applied the migritions by executing VisualStudio with this account. Then a schema for this special account is created and thereafter it can access the database fro the webserver application. It works since this special account is currently the only one that needs direct access to the database (besides myself). But this should ne be a permanent solution. </p>
  
  <p>Does anyone know a solution for this? The database has been created in the exactly same manner as for previous EF6 projects. 
  Why are the per user schemas only used when applying the migrations to the production system and not on my development machine and how can I control the schema manually? 
  I tried <code>modelBuilder.HasDefaultSchema("dbo");</code> but this does not work. Actually it seems to not having any effect at all.</p>