Add SystemJS and Emitr as dependencies.
Add a HeaderStore to the HeaderElement package.

This is the Store of this component, Store as in the Flux pattern Store concept.
Similar to a model, holding the state and business logic for the component.
Register the new package dependencies, Emitr and SystemJS.
Export HeaderStore from the package main module.
Add system js script tag to workbench.
Add in Emitr paths configuration to load Emitr.