After a brief glance, it seems you are almost there, but Bootstrap's CSS is overpowering your own. Within Bootstrap, we have:
.carousel-control .glyphicon-chevron-right{
...
display:inline-block;
}
If we were to label this situation with points, Bootstrap would be awarded '2 points' for applying the 'inline-block' style.
Solution could be as simple as adding an extra class (with 2 matching points from Bootstrap) before ".glyphicon-chevron-right", as your CSS loads after Bootstrap.
.carousel .glyphicon-chevron-right{display:none;}
Alternatively, for a more forceful override, utilizing an ID in front grants a higher value (approximately 256).
#myCarousel .glyphicon-chevron-right{display:none;}