Update TTRangeSlider.h
Update TTRangeSlider.h

- move minLabel and maxLabel, maybe someone need to modify label text by programmatically
WenryXu/TTRangeSlider,mikeMTOL/TTRangeSlider,WenryXu/TTRangeSlider,tianfan/TTRangeSlider,chengkaizone/TTRangeSlider,tianfan/TTRangeSlider,fiantinangon/TTRangeSlider,TomThorpe/TTRangeSlider,chengkaizone/TTRangeSlider,apaganobeleno/TTRangeSlider,WenryXu/TTRangeSlider,apaganobeleno/TTRangeSlider,Instamotor-Labs/TTRangeSlider,tianfan/TTRangeSlider,protspace/TTRangeSlider,fiantinangon/TTRangeSlider,apaganobeleno/TTRangeSlider,protspace/TTRangeSlider,fiantinangon/TTRangeSlider,chengkaizone/TTRangeSlider,protspace/TTRangeSlider,mikeMTOL/TTRangeSlider,mikeMTOL/TTRangeSlider,Instamotor-Labs/TTRangeSlider,Instamotor-Labs/TTRangeSlider