title: Couldn't find 'project.json' in current directory on dotnet build
body: <p>i have a visual studio asp.net core v1.1 solution and want to build it with the 'developer command prompt for VS 2017'. Therefore i am using the following commands:</p>
  
  <ul>
  <li>cd (path\rootfolder of the VS Project)</li>
  <li>dotnet build</li>
  </ul>
  
  <p>The result is always: <strong>Couldn't find 'project.json' in current directory</strong></p>
  
  <p>My <strong>dotnet --info</strong> result is:</p>
  
  <ul>
  <li>.NET Command Line Tools (1.0.0-preview2-1-003177)</li>
  </ul>
  
  <p>The Project has no project.json file due its usage of asp.net core v1.1. So all projects within the Solution have their own *.csproj files.</p>
  
  <p>Does anyone have an Idea what could possibly go wrong?</p>