Contexts passed to the Event initializer may not be Raven Contexts

I was using raven with Sidekiq (and that works fine). When you add SideTiq to the mix, it calls SideKiqs handle_exception with a String context that is passed on to Raven. Something like so:

` handle_exception(e, context: "Sidetiq::Handler#dispatch") `

This causes the event initializer to blow up when the String doesn't respond to the user method. I don't think it's safe to assume whatever context passed in is a raven context. This solution solved this particular case, but still isn't ideal. I think namespacing the options might be safer.