Fixes #28. Workaround for PreviewView to handle getModel method.
Fixes #28. Workaround for PreviewView to handle getModel method.

Fixed issue that caused toggling preview to error because it
was missing getModel method that is expected for an EditorView.

lasaro-dumer/atom-preview,zuren/atom-preview,Glavin001/atom-preview,lasaro-dumer/atom-preview,Glavin001/atom-preview,lasaro-dumer/atom-preview,zuren/atom-preview,zuren/atom-preview,Glavin001/atom-preview