refactored scss to include easily brandable overrides to the sites generic styling. also added a new file to override boostrap and added a section at bottom of dmproadmap variable file for new variables DMPRoadmap/roadmap#573

pulled bootstrap in and updated basic header/footer/main content to use the grid system. Updated static pages, home page and contact us page to use grid system DMPRoadmap/roadmap#552

front-end dependencies handled through npm. DMPRoadmap/roadmap#551