Dropzone path incorrect when image is dropped onto bootstrap-markdown text area

[webdevbrian]

This is a bug with the success callback of the image upload in the bootstrap-markdown plugin, it's calling just "path" however path is an object, so the fix is to append "path.url".

The fix (around line 482):
textarea.val(text.substring(0, caretPos) + '\n![description](' + path.url + ')\n' + text.substring(caretPos));

I'll make a PR for this later on, but just incase I get hit by a car and someone else has the same bug trying to incorporate dropzone :)

[webdevbrian]

Here's the PR for this : #259