image not loading
**Which version of the plugin are you using?**
[ ] Data Populator for Adobe XD

**Describe the bug**
When using the "Populate with preset" option it doesn't seem to want to load {image} from the url. It just loads the url as plain text (or rather text styled however I have it in the XD file).

**To Reproduce**
Steps to reproduce the behavior:

Create a {image} placeholder
1. Go to 'populate with preset'
2. Click on 'populate'
3. See error

**Expected behavior**
An image should be loading in the appropriate tag
<img width="561" alt="screen shot 2018-10-18 at 10 04 41 pm" src="https://user-images.githubusercontent.com/967810/47180906-eab65700-d321-11e8-85db-c9328756656e.png">



**Screenshots**
If applicable, add screenshots to help explain your problem.

**Environment (please complete the following information):**
 - macOS Version: [e.g. macOS High Sierra 10.13.5]
 - Sketch Version [e.g. Sketch 52.2] or Adobe XD Version [e.g. Adobe XD 13.0.0.0]
 - Plugin Version [e.g. 3.0.0]
