Update Travis build to run on Trusty
Update Travis build to run on Trusty

stuha/wbr-zsh,janlazo/fzf,junegunn/fzf,junegunn/fzf,janlazo/fzf,infokiller/fzf,wilywampa/fzf,junegunn/fzf,wilywampa/fzf,infokiller/fzf,infokiller/fzf,wilywampa/fzf,janlazo/fzf