title: Merge binary columns and keep the one
body: <p>I have two binary columns:</p>
  
  <pre><code>col1 col2
  0      1
  0      0
  1      0
  1      1
  </code></pre>
  
  <p>I would like to merge this columns and if value 1 exist into one of in both columns I would like to have the 1 value. Example of output</p>
  
  <pre><code>merged_col
  1
  0
  1
  1
  </code></pre>
  
  <p>The general merged I tried is this:</p>
  
  <pre><code>merge(df$col1, df$col2, all = TRUE)
  </code></pre>
  
  <p>Any idea how can I handle the values?</p>