title: ggrepel: plot labels above points
body: <p>I want to plot labels precisely above points where possible (no overlap), but ggrepel seems to insist on plotting slightly above or below.  E.g.</p>
  
  <pre><code>require(ggplot); require(ggrepel)
  
  ggplot(iris[1:10,], aes(Sepal.Length, Sepal.Width)) + 
    geom_point(pch=1, size=8) +
    geom_text_repel(aes(label=Species), segment.color=NA, 
                    point.padding=unit(0, "lines")) 
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/SkgTc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SkgTc.png" alt="enter image description here"></a></p>
  
  <p>You can of course reduce the <code>force</code> argument, but then labels don't repel each other when they <em>do</em> overlap.</p>