Fixed cargo and rust warnings
Fixed cargo and rust warnings

JohnColanduoni/gfx,alexcrichton/gfx,mitchmindtree/gfx-rs,sectopod/gfx-rs,Bastacyclop/gfx,JohnColanduoni/gfx,ColinKinloch/gfx,red75prime/gfx,tanderegg/gfx,gfx-rs/gfx-rs,davll/gfx,ColinKinloch/gfx,tanderegg/gfx,aepsil0n/gfx-rs,bvssvni/gfx-rs,tempbottle/gfx