title: Cannot find any scalar summaries in TensorBoard
body: <p>I am doing mnist tutorial, and fully_connected_feed.py works and saves events.out.tfevents.1447186888 file to ~..\data\
  when I trying to open TensorBoard like this </p>
  
  <pre><code>python ~/tensorflow/tensorflow/tensorboard/tensorboard.py --logdir=~/tensorflow/tensorflow/g3doc/tutorials/mnist/data 
  </code></pre>
  
  <p>or like this </p>
  
  <pre><code>tensorboard --logdir=~/tensorflow/tensorflow/g3doc/tutorials/mnist/data
  </code></pre>
  
  <p>It opens, but then I see  "No scalar summary tags were found." </p>