Fixed issue with animation adding more keyframes than necessary. Added more animations. Added timing Fuction for animations

-----mixins.scss----

Added animation-timing-function for animations where default is 'ease'
(line 260-268).

Added animations:
• lightSpeedIn
• lightSpeedOut

Fixed issue where animation mixin would add more @keyframes than
necessary. Should now only do it once (line 278).

----- index.html -----
Added several demo animations (lines 13-21).

----- master.scss ----
Included animate mixins for animation demos (lines 49-58).