You might have tried various styling to arrange your icons, but you need to target your icons i.e. i tag as below and style,
.footer-links > li > a > i{
vertical-align:middle;
}
Check this two jsFiddle, I have added background to one just for understanding purpose.
https://jsfiddle.net/dbwaoLrh/2/
https://jsfiddle.net/dbwaoLrh/4/