title: Tensorflow - casting from int to float strange behavior
body: <p>I am working on tensorflow 0.12 and am having problem with casting.
  The following snippet of code does a strange thing:</p>
  
  <pre><code>sess = tf.InteractiveSession()
  a = tf.constant(1)
  b = tf.cast(a, tf.float32)
  print b.eval()
  </code></pre>
  
  <p>I get a value:
  6.86574233e-36</p>
  
  <p>I also tried using <code>tf.to_float()</code> and <code>tf.saturate_cast</code>. Both gave the same result.</p>
  
  <p>Please help.</p>