README: remove `.svg` from shields.io badges
README: remove `.svg` from shields.io badges

coliff/bootstrap,inway/bootstrap,GerHobbelt/bootstrap,inway/bootstrap,tjkohli/bootstrap,tjkohli/bootstrap,m5o/bootstrap,coliff/bootstrap,twbs/bootstrap,GerHobbelt/bootstrap,GerHobbelt/bootstrap,twbs/bootstrap,m5o/bootstrap,inway/bootstrap