Fetches epics in Roadmap via Graph query including
support for filters.

Rename Roadmap app root component and bootstrap script file to have a
specific name for easier debugging while using sourcemaps in browser.

Update Vuex implementation to ensure Roadmap is re-rendered
based on state change during browser window resize.

Add actions for fetching epics on Roadmap and remove object Store
and Service classes.

Adds skeleton loader for Epics on default load.
Makes re-rendering Epics more efficient.

Makes Roadmap timeline dynamic to be always
scrollable on any screen size.
Fetches new epics as user scrolls into past or future and renders it.

Signed-off-by: Rémy Coutable <remy@rymai.me>