 Guard::Jekyll failed: Illegal nesting: nesting within plain text is illegal.

I am using this plugin with guard-jekyll. I get this error whenever I try to use the partial syntax from a page template. 

```
# index.haml
{% haml navbar.haml %}
```

It works fine when I use it from a layout template

```
# _layouts/default.haml
{% haml navbar.haml %}
```
