Added image assets

The header and background slice jpegs
Added pure css

Added pure css libs to project and add initial vars to variables scss
Merge pull request #19 from impact100/feature--add-image-assets

Added image assets
Merge pull request #18 from impact100/feature-pure

Added pure css
testing highline gem on heroku
Merge pull request #20 from impact100/initial_admin_registration

testing highline gem on heroku
fix: Path for vendor CSS