title: rename all columns in list of data frames
body: <p>I have a list of dataframes </p>
  
  <pre><code>vars &lt;- c("Col_1", "Col_2", "Col_3")
  
  list_df &lt;- list(
    tibble(
      a = 1,
      b = 2,
      c = 3
    ),
    tibble (
      d = 1,
      e = 2,
      f = 3
    )
  )
  </code></pre>
  
  <p>And I'd like to rename the columns using the <code>vars</code> but I think I'm missing something here. </p>
  
  <pre><code>map(list_df, ~rename_all(.x, vars))
  </code></pre>
  
  <p>The result should be:</p>
  
  <pre><code>list(
    tibble(
      Col_1 = 1,
      Col_2 = 2,
      Col_3 = 3
    ),
    tibble (
      Col_1 = 1,
      Col_2 = 2,
      Col_3 = 3
    )
  )
  </code></pre>
  
  <p>I'd like this to work regardless of the initial column names (and all data frames will always only have three columns. Is this possible?</p>