title: Turn a tibble into a named vector in R
body: <p>I'd like to turn a tibble in R (portion of it is shown below) into a named vector, where each unique <code>gs_name</code> maps to a list of <code>ensembl_gene</code>s corresponding to it. How can I do this?</p>
  <pre><code># A tibble: 6 x 2
    gs_name                  ensembl_gene  
    &lt;chr&gt;                    &lt;chr&gt;         
  1 ABBUD_LIF_SIGNALING_1_DN WBGene00002717
  2 ABBUD_LIF_SIGNALING_1_DN WBGene00006518
  3 ABBUD_LIF_SIGNALING_1_DN WBGene00000542
  4 ABBUD_UP WBGene00000546
  5 ABBUD_UP WBGene00013434
  6 ABBUD_UP WBGene00001579
  </code></pre>