Update coffee-script-source, sass, foreman

* foreman (0.75.0 > 0.74.0)
* guard-jekyll-plus (1.4.10 > 1.4.9)
* coffee-script-source (1.8.0 > 1.7.1)
* minitest (5.4.1 > 5.4.0)
* sass (3.4.2 > 3.4.1)
Update Sass variables per latest version of mockups
Stub out major pages and update navigation links accordingly
Fix home page call to action link and styling
Split out base and navigation styles to separate stylesheets
Add responsive mixins
Add Flexbox layout
Temporarily remove slider from home page
adjust call to actions
add thanks page
simplify contact form styling
Clean up home page, style navigation footer, add social media icons
Add Location page
default font size to 16px