title: Specify which project file to use when inside project directory
body: <p>Trying to use "dotnet ef" command in Package Manager Console.
  the PMC is cd to the .csproj directory, and still getting:</p>
  
  <pre><code>dotnet : Specify which project file to use because this 'C:\Users\PC-NAME\Source\Repos\TestProject\Test" contains more than one project file.
  At line:1 char:1
  
  dotnet ef migrations add TestMigration
    + CategoryInfo          : NotSpecified: (Specify which p...e project file.:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError
  </code></pre>
  
  <p>Tried use -p / --p and point to the .csproj file / directory - still same error.</p>
  
  <p><strong>Using .NET CORE, MVC project, Latest EF Core 2.0.2 version.</strong></p>
  
  <p><strong>There's no so much valuable data</strong> 
  on the internet about that problem, just a wild guess
  that dotnet ef command is looking for .exe file to run on.</p>
  
  <blockquote>
    <p>Hoping for help.</p>
  </blockquote>