Leak canary integration sample

[bangarharshit]

Thanks for the library. It looks really simple and easy to use.

I wrote a quick example to show how Leak canary can be integrated into LeakCanary. The only problem is onHide is final in RX screen. A solution is to use @callsuper instead of onFinal. Not sure if it is of utility to you guys but will be interested in your suggestion.

Another utility of have onHide exposed is that any custom cleanup goes here.

Opened up a PR - #46