Add Info highlights for ALE plugin

colors/gruvbox.vim

@@ -811,9 +811,11 @@ call s:HL('BufTabLineFill', s:bg0, s:bg0)
 
 call s:HL('ALEError', s:none, s:none, s:undercurl, s:red)
 call s:HL('ALEWarning', s:none, s:none, s:undercurl, s:yellow)
+call s:HL('ALEInfoLine', s:none, s:none, s:undercurl, s:blue)
 
 hi! link ALEErrorSign GruvboxRedSign
 hi! link ALEWarningSign GruvboxYellowSign
+hi! link ALEInfoSign GruvboxBlueSign
 
 " }}}