title: How to read multiple lines of a file into one row of a dataframe
body: <p>I have a data file where individual samples are seperated by a blank line and each field is on  it's own line:</p>
  
  <pre><code>age 20
  weight 185
  height 72
  
  age 87
  weight 109
  height 60
  
  age 15
  weight 109
  height 58
  
  ...
  </code></pre>
  
  <p>How can I read this file into a dataframe such that each row represents a sample with columns of age, weight, height?</p>
  
  <pre><code>    age    weight    height
  
  1   20      185        72  
  2   87      109        60
  3   15      109        58
  ...
  </code></pre>