title: msbuild fails to compile vsto project
body: <p>We recently installed a new development environment (Windows 10) from scratch with Visual Studio 2017 but we cannot manage to make <code>msbuild</code>  compile a Microsoft Office Addin for Word (vsto). 
  Within the Visual Studio installer we made sure to include the required components for Office Development.</p>
  
  <p>It throws the following error (german translated to english)</p>
  
  <blockquote>
    <p>error MSB4226: The imported project "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\Microsoft\VisualStudio\v15.0\OfficeTools\Microsoft.VisualStudio.Tools.Office.targets" was not found. Also, tried to find "OfficeTools\Microsoft.VisualStudio.Tools.Office.targets" in the fallback search path(s) for $(VSToolsPath) - "C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v15.0" [...]</p>
  </blockquote>
  
  <p>However, the project builds fine within Visual Studio.</p>
  
  <p>On the old system, everything works fine, and i cannot remember having to configure anything at all.</p>