title: vim-go autocompletion not working
body: <p>I recently installed <a href="https://github.com/fatih/vim-go" rel="noreferrer">vim-go</a> using pathogen, but the autocompletion feature is not working. If I am using  it only shows commands I've already used.
  My .vimrc has </p>
  
  <pre><code>filetype plugin on
  
  " Enable autocompletion
  set omnifunc=syntaxcomplete#Complete
  " Select keyword as you type
  :set completeopt=longest,menuone
  </code></pre>
  
  <p>Do I need more than just this plugin? The other feature I have tested so far are working (:GoRun, syntax highlighting).
  This is on a Ubuntu machine.</p>