title: Combine Consecutive Rows with the Same column values
body: <p>I have something that looks like this.
  How do I go from this:</p>
  
  <pre><code>    0             d
  0   The         DT
  1   Skoll       ORGANIZATION
  2   Foundation  ORGANIZATION
  3   ,           ,
  4   based       VBN
  5   in          IN
  6   Silicon     LOCATION
  7   Valley      LOCATION
  </code></pre>
  
  <p>to this:</p>
  
  <pre><code>    0                       d
  0   The                     DT
  1   Skoll Foundation        ORGANIZATION
  3   ,                       ,
  4   based                   VBN
  5   in                      IN
  6   Silicon Valley          LOCATION
  </code></pre>