title: Fabricjs textbox fontfamily changes when writing text
body: <p>I am  facing an issue as when I select a text and change font family for that specific selected text in a textbox and then start writing with the selection enabled on the selected text. The textbox is not picking the last changed fontfamily. Use case steps are:
  1. insert a text box and write some text like "Fabricjs is a good library". At this point text fontfaily is TimeNewRoman.
  2. Now make a selection on a text like select a word library and change its fontfamily to Arial. 
  3. Now if you start typing on the selection enabled text(library) whose  fontfamily is changed is the previous step, the newly type text is not picking up the Arial fontfamily instead it is written in TimeNewRoman.</p>
  
  <p><a href="http://fabricjs.com/test/misc/itext.html" rel="nofollow">http://fabricjs.com/test/misc/itext.html</a></p>
  
  <p>Select a text object Apply style like bold to a selective text and then write some text on the same bold selective text. Its not writing in bold style.  </p>
  
  <p>Kindly share a way to handle this issue. Any thoughts on this please share.</p>
  
  <p>Thanks.</p>