Update Logos in the Footer

The logos in the footer are ancient. The webtech logo should be [this](https://github.com/wtg/propaganda/tree/master/WebTech%20logo) one and should link to https://webtech.union.rpi.edu/. The senate logo should be [this](https://surveys.union.rpi.edu/static/primary_student_senate.svg) and should link to https://sg.rpi.edu/about/senate