vimrc: YCM only if python3 enabled

.vimrc

@@ -36,6 +36,7 @@ if filereadable(expand(vundle_dir) . "/README.md")
     Plugin 'tell-k/vim-autopep8'
     Plugin 'jpalardy/vim-slime'
     Plugin 'preservim/tagbar'
+    Plugin 'wellle/context.vim'
 
     call vundle#end()            " required
 else
@@ -343,6 +344,10 @@ nmap <F2> :NERDTreeToggle<CR>
 nmap <F3> :NERDTreeFind<CR>
 map <F5> :call CurtineIncSw()<CR>
 
+let g:context_enabled = 0
+map <F6> :ContextToggle<CR>
+map cp :ContextPeek<CR>
+
 " Julialang
 let g:latex_to_unicode_auto = 1