Fix icons to be responsive on mobile

[debragail]

When viewing the site on mobile the icons in HeaderSections do not resize.

Expected Behavior

Icons should fit within the box and scale based on mobile width.

Current Behavior

They do not resize and are outside the container.

Possible Solution

create rule for mobile width.

Steps to Reproduce (for bugs)

1. Resize browser to mobile width or view on mobile device

Context

Must make the site responsive.

Your Environment

Google Chrome: Version 70.0.3538.110 (Official Build) (64-bit) Mac OSX Yosemite (lol I kno)

[TalAter]

We don't really need mobile support. But it still might be nice to make these icons responsive to support various screens.