Add wrappers for SDL 2.0.9 rumble functions

[Manorhos]

I added sdl2::controller::set_rumble and sdl2::joystick::set_rumble, wrappers for the two new (since SDL 2.0.9) rumble functions SDL_GameControllerRumble and SDL_JoystickRumble respectively.
The game-controller and joystick examples were also extended to test them a little.

[Manorhos]

Travis seems to fail without the bundled feature, because the script for installing SDL2 still seems to download version 2.0.8...

[Cobrand]

Weird that we didnt catch that earlier. Can you update the travis file to use 2.0.9 real quick?

[Manorhos]

Yeah, I'll do that.

[Cobrand]

For the changelog, technically, 0.32 is already released, so make a new category "v0.32.1 (unreleased)" and put those changes there instead. Otherwise, people will wonder why this rumble feature is not part of 0.32 on crates.io.

Other than than, looks good to me! I tested the update example locally on my computer with a Xbox 360 controller, works really well!

[Manorhos]

Yeah, I wasn't so sure about that myself... What you proposed sounds good, I'm gonna do that.

Edit: Oh, and I'm glad it also works fine for you! The 2.0.9 rumble feature really is great, especially with the HIDAPI stuff they added.