title: Trying to use migrations in a project other then the startup project results in error
body: <p>Hi I am trying to take advantage of Entity Framework migrations but when I add this command:</p>
  
  <blockquote>
    <p>PM> Add-Migration</p>
    
    <p>cmdlet Add-Migration at command pipeline position 1</p>
    
    <p>Supply values for the following parameters:</p>
    
    <p>Name: CodeArtMigration</p>
  </blockquote>
  
  <p>I get back this error message:</p>
  
  <blockquote>
    <p>Cannot determine a valid start-up project. Using project 'CodeArt.DataAccess' instead. Your configuration file and working directory may not be set as expected. Use the -StartUpProjectName parameter to set one explicitly. Use the -Verbose switch for more information.
    No packages installed.
    The EntityFramework package is not installed on project 'CodeArt.DataAccess'.</p>
  </blockquote>
  
  <p>The last part of the message that says that Entity Framework is not available in he current project is not true because I do have a reference to Entity Framework.</p>
  
  <p>The package source is set to Microsoft and .NET but I als
  My code is structured in 3 layers I wanted to add the migration data in my DataAccess layer.Also I wanted to minimize thereference to Entity Framework only in my data access layer.</p>