Redactor: ImageTag config -> Inline images

Hi,

I'm trying to add an image in my paragraph with redactor, but he creates a new figure element outside the paragraph tag. Is it possible to place it in the paragraph tag? I've read on https://imperavi.com/redactor/docs/settings/images/#setting-imageTag that there should be a way to set the imageTag.
I've set this to span in my redactor config:

{
"buttons": ["formatting", "bold", "italic", "unorderedlist", "orderedlist", "link", "image"],
"plugins": ["source", "fullscreen"],
"formatting": ["p", "h1"],
"toolbarFixed": true,
"linebreaks": true,
"imageTag": "span"
}

When I add an image to the redactor field it still wraps a figure tag around it ->

<div class="redactor-layer redactor-styles redactor-layer-img-edit redactor-in" aria-labelledby="redactor-voice-0" role="presentation" id="redactor-uuid-0" contenteditable="true" spellcheck="true" dir="ltr" style="min-height: 40px;">

<p>Test</p><figure><img src="http://localhost/uploads/content/Gear.png#asset:657">​</figure>

</div>

Craft version: Craft Pro 3.0.0-RC7.1
Redactor version: 1.0.1