call refresh function on window resize event
call refresh function on window resize event

fixes #1144

bling/vim-airline,tschundler/dotfiles,vim-IDE/vim-airline,dalguji/vim-airline,unphased/vim-airline,HarmtH/vim-airline,chrisbra/vim-airline,rchicoli/vim-airline,tschundler/dotfiles,yzhou61/vim-airline,tschundler/dotfiles