Clear the file input prior to triggering it

This ensures the change event is fired even if the file didn't change

Fixes #2

app/index.html

@@ -107,8 +107,10 @@
         <div class="row">
             <div class="col-lg-12">
                 <center>
-                    <input type='file' v-el:upload style="display: none" id="uploadInput"/>
+                    <form id="fileUploadForm">
+                        <input type="file" v-el:upload style="display: none" id="uploadInput"/>
                         <button class="btn btn-primary" v-on:click="upload()" id="uploadButton">Upload</button>
+                    </form>
                 </center>
                 <br/>
             </div>

app/js/app.js

@@ -143,6 +143,9 @@ function upload() {
         });
     });
 
+    // reset the form first to make the change handler retrigger even on the same file selected
+    $('#fileUploadForm')[0].reset();
+
     app.$els.upload.click();
 }