specs_time

time resource for specs

```rust extern crate specs_time;

use specs_time::{Time, TimeSystem};

let mut world = World::new();

world.add_resource(Time::::new());

let mut dispatcher = DispatcherBuilder::new() .add(TimeSystem::::new(), "time_system", &[]) .build();

dispatcher.dispatch(&mut world.res); asserteq!(world.readresource::>().frame, 1); ```