Estou tentando usar o EF6 alpha e o SQLite 1.0.66.0

Meu arquivo .config:

<connectionStrings>
   <add connectionString="data source=:memory:;" name="TestDbContext" providerName="System.Data.SQLite" />
</connectionStrings>
<entityFramework>
   <providers>
      <provider invariantName="System.Data.SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite, Version=1.0.66.0, Culture=neutral, PublicKeyToken=db937bc2d44ff139" />
   </providers>
</entityFramework>
<runtime>
   <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
     <dependentAssembly>
        <assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.0.0.0" newVersion="5.0.0.0" />
     </dependentAssembly>
   </assemblyBinding>
</runtime>
<system.data>
  <DbProviderFactories>
     <remove invariant="System.Data.SQLite"/>
       <add name="SQLite Data Provider" invariant="System.Data.SQLite"
           description=".Net Framework Data Provider for SQLite"
           type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite, Version=1.0.66.0, Culture=neutral, PublicKeyToken=db937bc2d44ff139" />
  </DbProviderFactories>
</system.data>

Quando eu corro

using (var dbContext = new TestDbContext())
{
    if (dbContext.Database.Exists())
    {
        dbContext.Database.Delete();
    }
    dbContext.Database.Create();
}

Eu recebo um erro:

System.InvalidOperationException: System.InvalidOperationException: O membro 'Instância' do tipo de provedor Entity Framework 'System.Data.SQLite.SQLiteFactory, System.Data.SQLite, Versão = 1.0.66.0, Culture = neutral, PublicKeyToken = db937bc2d44ff139' não retorna um objeto que herda de 'System.Data.Entity.Core.Common.DbProviderServices'. Os provedores do Entity Framework devem se estender a partir dessa classe e o membro 'Instance' deve retornar a instância do Singleton do provedor.

O que estou fazendo de errado?