Added

• New brand icon stackpath

Changed

• Updated redhat, mailchimp brand icons
• Updated Facebook brand icons in accordance with http://facebookbrand.com (facebook, facebook-f, facebook-square)
• Updated Git brand icons (git, git-square, git-alt)
• Removing the "at" character to prevent overlap with the at icon

Fixed

• Missing version for the route icon FortAwesome/Font-Awesome#13804
• Corrected the orientation of radiation and radiation-alt icons
• Alignment fixed for check-double
• Moved the notch into the correct location for sim-card
• Allow the role attribute to be specified FortAwesome/Font-Awesome#14791
• Prevent IE11 CSS selector error from crashing SVG with JS execution