add startups images and descriptions to jobfair page

:red_circle: This shouldn't be merged until we get a better companies.json :red_circle: 

Note: we can :recycle: images from [last year](https://github.com/adicu/adicu.github.com/tree/master/img/jobfair)

![startup career fair adi the application development initiative](https://cloud.githubusercontent.com/assets/2433509/4514729/3cf5bf44-4b89-11e4-8d27-ede786120872.png)