Update GPA requirement to 2.0 from 2.5

The current [consitution guide][1] states 2.0 as a required minimum. We
aren't an honors society, so might as well stick to the minimum.

[1]: http://si.gmu.edu/wp-content/uploads/2013/07/RSO-Constitution-Guide1.pdf
Status Job ID Name Coverage
  Test
passed #634
compile_pdf

00:00:20