Rethink design of RunBot

[pmonks]

Currently, RunBot uses reflection to start each bot, but this is non-intuitive for newcomers to Symphony and the symphony-java-client, and doesn't promote best practices in their own bots (reflection being generally considered bad practice in Java).

[pmonks]

Background: during the Open Innovation Challenge Silicon Valley, one team lost approximately an hour trying to figure out why their main method wasn't taking effect (they'd copied-and-modified the HelloWorldBot). Turns out that main moved to RunBot, but had been left in HelloWorldBot. As soon as I discovered that I ripped main out of all of the individual bot (to try to minimise confusion in the future), but there was still some confusion about how RunBot worked, even after we'd figured out that particular problem.

[maoo]

The develop branch is ready for a review on this. TY for raising the issue @pmonks !