Modifications to dropwizard-guice to work with latest Guice4.0-beta5

I am using Java8 on my dropwizard-based project and I'm running into a lot of problems with Guice3.0 but it has been fixed on the latest beta.

https://code.google.com/p/google-guice/issues/detail?id=757

I encountered this bug very frequently and it was driving me mad. Luckily, it seems that Guice40 is backwards compatible and all I had to do was remove the jersey-guice dependency because they are not keeping up with Guice40 beta.

cc @HiJon89 @wsorenson 

Maybe we can publish this is a new-version snapshot?