added previm plugin

.vimrc

@@ -17,6 +17,8 @@ Plugin 'itchyny/lightline.vim'
 Plugin 'airblade/vim-gitgutter'
 
 Plugin 'altercation/vim-colors-solarized'
+
+Plugin 'kannokanno/previm'
 " All of your Plugins must be added before the following line
 call vundle#end()            " required
 filetype plugin indent on    " required
@@ -50,12 +52,10 @@ set ruler
 set undolevels=1000
 set backspace=indent,eol,start
 set colorcolumn=80
+
 " lastline plugin config
 set laststatus=2
-"let g:lightline = {'colorshceme': 'solarized dark'}
-" gitgutter
-let g:gitgutter_realtime = 1
-let g:gitgutter_eager = 1
+
 " colorscheme
 syntax enable
 "set background=dark
@@ -65,3 +65,4 @@ highlight colorcolumn ctermbg=grey ctermfg=blue
 highlight OverLength ctermbg=red ctermfg=white
 match OverLength /\%>80v.\+/
 filetype plugin on
+nmap ne :NERDTreeToggle<cr>