title: missing information in tibble
body: <p>Taking the 'mtcars' data and moving it into a tibble</p>
  <pre><code>data&lt;- tibble(mtcars)
  </code></pre>
  <p>Noted that the first column which was the vehicle make has now become in the tibble just a numeric list 1,2,3 etc</p>
  <p>Fairly new to R so is there a way to tell a tibble to keep the format of the original data?</p>