Merge branch 'release/0.6.0' into develop
Update keywords in package.json to include handlebars.
Minor layout change in README.
Create renderFile() method using render() if it exists.
Add Haml.
Merge branch 'feature/map-renderfile' into develop
Refactor renderFile() and render().

Pushed the Haml-specific code down a level to make it easier to conditionally switch behaviour.
Allow module value in config to be optional.
Allow restructure of options to be configurable.
Allow synchronous render() methods to called asynchronously.
Add Liquid.
Bump version number.
Update changelog.
Merge branch 'release/0.7.0'