fix selected bar position issue. 
fix selected bar position issue. 
luvacu/XLPagerTabStrip,functionaldude/XLPagerTabStrip,gudjao/XLPagerTabStrip,luvacu/XLPagerTabStrip,xmartlabs/XLPagerTabStrip,gudjao/XLPagerTabStrip,functionaldude/XLPagerTabStrip,xmartlabs/XLPagerTabStrip