title: How to remove the existing file dropzone?
body: <p>I have this sample:</p>
  
  <p><a href="http://codepen.io/anon/pen/jqWJWd" rel="noreferrer">link</a></p>
  
  <p><strong>CODE HTML:</strong></p>
  
  <pre><code>&lt;div class="dropzone dz-clickable" id="myDrop"&gt;
       &lt;div class="dz-default dz-message" data-dz-message=""&gt;
            &lt;span&gt;Upload or drag patient photo here&lt;/span&gt;
       &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><strong>CODE JS:</strong></p>
  
  <pre><code> Dropzone.autoDiscover = false;
   var myDropzone = new Dropzone("div#myDrop", {
     addRemoveLinks: true,
     url: "#",
     maxFiles: 1,
     init: function() {
  
       this.on("maxfilesexceeded", function(file) {
         alert("You are not allowed to chose more than 1 file!");
         this.removeFile(file);
  
       });
  
       this.on("addedfile", function(file) {
         myDropzone.options.removefile.call(myDropzone, mockFile);
         //  I want to delete an existing element
       });
  
     }
   });
  
   var fileName = $('#profilePicture').val();
   var mockFile = {
     name: fileName,
     size: 12345
   };
   myDropzone.options.addedfile.call(myDropzone, mockFile);
   myDropzone.options.thumbnail.call(myDropzone, mockFile, "https://lh3.googleusercontent.com/-eubcS91wUNg/AAAAAAAAAAI/AAAAAAAAAL0/iE1Hduvbbqc/photo.jpg?sz=104");
  </code></pre>
  
  <p>What I want to do is when the user uploads a file, then the existing one to be removed.</p>
  
  <p>How can you do this correctly?</p>
  
  <p>Thanks in advance!</p>