Added more specific regex for demo.css import
Added more specific regex for demo.css import

vaadin-bower/vaadin-components,vaadin/vaadin-components,vaadin/vaadin-components,vaadin/vaadin-components,vaadin/vaadin-core-elements,vaadin/vaadin-elements,vaadin/vaadin-elements,vaadin-bower/vaadin-components,vaadin/vaadin-elements,vaadin-bower/vaadin-components,vaadin/vaadin-core-elements