title: Cannot use HttpClient in a portable class library
body: <p>I've installed Microsoft HTTP Client Lib via nugget but I cannot use the <code>HttpClient</code> class. It does not see the namespace <code>System.Net.Http</code>. I'm new to .net/microsoft platform. The project is based on the.net portable library.</p>
  
  <p><img src="https://i.stack.imgur.com/Myfii.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/HucwP.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/VKLsB.png" alt="enter image description here"></p>