title: VS2017 publishing error when compiling TypeScript
body: <p>I am working on a project using Promises and targeting ES5.  In my .csprog, I have an xml tag of:</p>
  
  <pre><code>   &lt;TypeScriptLib&gt;ES6,ES5,DOM&lt;/TypeScriptLib&gt;
  </code></pre>
  
  <p>This has been working fine for, well forever until today.  Today I open up VS and I cant publish the project because of this build error:</p>
  
  <pre><code>An async function or method must return a 'Promise'. Make sure you have a declaration for 'Promise' or include 'ES2015' in your `--lib` option
  </code></pre>
  
  <p>So I changed my .csproj tag to:</p>
  
  <pre><code>    &lt;TypeScriptLib&gt;ES6,ES5,DOM,ES2015&lt;/TypeScriptLib&gt;
  </code></pre>
  
  <p>and I'm still receiving the same error.  And this happens on publish only, it builds fine and all the typescript files compile as well (debugging works too), these errors only show up on publish.</p>
  
  <p><strong>edit:</strong>  I was able to get the error to go away by jumping through random VS hoops, but then it returned with no explanation.  So now moved to a tsconfig.json file and the errors went away, BUT the compile on save doesn't generate a js file even though it indicates successful generation. 
  I now moved the compilation to use gulp-typescript and it works fine.</p>