Added a waiting list

Hi, 

I talked to Alex about the Africa trip and I thought it sounded very interesting. I've wanted to go down there for 1-2 years now but never got around to it.

As per Alex' suggestion, the best way to put myself on the waiting list was simply to add a waiting list to the website and make a pull request, so here it is :-)

I have a friend who has a startup accelerator in Nairobi (Kresten Buch, http://www.88mph.ac/), maybe you already know him (or his accelerator) as he was based in Berlin for a while. He also has a football club in a neighboring city, which I guess could be a fun non-tech event (http://www.nakuruallstars.com/). I'll obviously be happy to make the introduction regardless of me joining the trip or not.

Thanks,
Tobias