Fixes else if statements in flexbox mixin
Fixes else if statements in flexbox mixin

mindeavor/bourbon,Jazz-Man/bourbon,jasonwalkow/bourbon,craftsmen/bourbon,setie/bourbon,mindeavor/bourbon,jasonwalkow/bourbon,greyhwndz/bourbon,chriseppstein/bourbon,nickg33/bourbon,ismarkunc/bourbon,thoughtbot/bourbon,chriseppstein/bourbon,smithdamen/bourbon,craftsmen/bourbon,zyj1022/bourbon,zyj1022/bourbon,cllns/bourbon,Nikeshsuwal/bourbon,greyhwndz/bourbon,smithdamen/bourbon,Jazz-Man/bourbon,nagyistoce/sass-bourbon.io,thoughtbot/bourbon,nickg33/bourbon,setie/bourbon