Better support for unit and app test modes

This release fixes problems with not finding HTML template files when the main Meteor app is in unit or app test mode.

1.4 node-sass compatibility

This release adds support for Meteor 1.4 apps by making it possible to use node-sass from npm if it's present in your app's package.json file as a dependency. This is now the recommended approach for 1.3+ Meteor apps.