The previous function only works for Chrome, these one works for Chrome, FF,
and Safari
function animateLine(elem) {
var offset = 0
elem.style.strokeDasharray = '6 1'
elem.style.strokeDashoffset = offset;
requestAnimationFrame(anim)
function anim() {
offset -= 0.2
elem.style.strokeDashoffset = offset
requestAnimationFrame(anim)
}
}