Changed image to .jpg and square.

I also removed the .png version and changed the index.html to use my
changes as well. I used the .jpg extension to save space.
Merge branch 'jtrosclair' of https://github.com/jtrosclair/fossasia.github.io into jtrosclair-jtrosclair

Conflicts:
	images/students/jerryt.png
	index.html
Merge branch 'jtrosclair-jtrosclair'