EF7 beta5: Error trying to insert child entity

I have created an API using ASP.NET5 and Entity Framework 7.0.0-beta 5.

I have the Model, DbContext and the Repository created as is described here, and when I try to insert data with a child entity my app throw an exception:

"Cannot insert the value NULL into column 'Status', table 'Company'; column does not allow nulls. INSERT fails."

The Status attribute is not null in my Company entity, but I don't know why EF is not capable of insert the value of the child entity. (in this case, "1")

This is the stack trace:

   at Microsoft.Data.Entity.Relational.Update.ReaderModificationCommandBatch.Execute(RelationalTransaction transaction, IRelationalTypeMapper typeMapper, DbContext context, ILogger logger)
   at Microsoft.Data.Entity.Relational.Update.BatchExecutor.Execute(IEnumerable`1 commandBatches, IRelationalConnection connection)
   at Microsoft.Data.Entity.Relational.RelationalDataStore.SaveChanges(IReadOnlyList`1 entries)
   at Microsoft.Data.Entity.ChangeTracking.Internal.StateManager.SaveChanges(IReadOnlyList`1 entriesToSave)
   at Microsoft.Data.Entity.ChangeTracking.Internal.StateManager.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Microsoft.Data.Entity.DbContext.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Microsoft.Data.Entity.DbContext.SaveChanges()
   at **.Data.Repositories.CompanyRepository.Create(Company company) in D:\**.Data\Repositories\CompanyRepository.cs:line 36
   at **.API.Controllers.CompanyController.Create(Company company) in D:\**.API\Controllers\CompanyController.cs:line 48

Here is the code:

DbContext

public class MrBellhopContext : DbContext
{

    public DbSet<Company> Company { get; set; }
    public DbSet<CompanyStatus> CompanyStatus { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Company>().Table("Company");
        modelBuilder.Entity<Company>().Key(c => c.CompanyId);
        modelBuilder.Entity<Company>().Index(c => c.Name);
        modelBuilder.Entity<Company>().Reference(c => c.Status).InverseReference().ForeignKey<CompanyStatus>(cs => cs.StatusId);

        modelBuilder.Entity<CompanyStatus>().Table("CompanyStatus");
        modelBuilder.Entity<CompanyStatus>().Key(cs => cs.StatusId);

        base.OnModelCreating(modelBuilder);
    }

}

Model

public class Company
{

    public int CompanyId { get; set; }

    public string Name { get; set; }

    public string Email { get; set; }

    public CompanyStatus Status { get; set; }

    public DateTime CreatedAt { get; set; }

    public DateTime UpdatedAt { get; set; }

}

public class CompanyStatus
{

    public int StatusId { get; set; }

    public string Name { get; set; }

}

Repository (only create method)

    public int Create(Company company)
    {
        _dbcontext.Add(company);
        _dbcontext.SaveChanges();

        return company.CompanyId;
    }

Does anyone know how to insert correctly child entities?