vimrc: add vim-gitgutter plugin, set default updatetime

.vimrc

@@ -24,6 +24,7 @@ Plugin 'https://github.com/tpope/vim-obsession'
 "Plugin 'https://github.com/pangloss/vim-javascript.git'
 "Plugin 'tikhomirov/vim-glsl'
 Plugin 'https://github.com/sheerun/vim-polyglot'
+Plugin 'https://github.com/airblade/vim-gitgutter'
 
 " All of your Plugins must be added before the following line
 call vundle#end()            " required
@@ -36,6 +37,7 @@ call vundle#end()            " required
 " some general vim settings
 filetype plugin indent on
 syntax on
+set updatetime=100
 colorscheme deus
 " change default deus function color
 hi! link Function deusAqua