title: cur_group_id () is not recognized as a function of dplyr on grouped data
body: <p>Here is my dataset:</p>
  <pre><code>   record_id voucher_number ice   sets 
         &lt;int&gt; &lt;chr&gt;          &lt;chr&gt; &lt;chr&gt;
   1         1 app1           app   app  
   2         1 00000          1     1    
   3         1 11111          1     2    
   4         1 22222          1     3    
   5         1 11111          2     4    
   6         2 app2           app   app  
   7         2 33333          1     1    
   8         2 44444          1     2    
   9         2 33333          2     3    
  10         2 33333          3     4    
  11         3 app3           app   app  
  12         3 55555          1     1    
  13         3 66666          1     2    
  14         3 55555          2     3    
  15         3 66666          2     4    
  16         3 55555          3     5    
  17         3 77777          1     6 
  
  </code></pre>
  <p>I am trying to create another variable column to represent different combinations of <code>record_id</code> and <code>voucher_number</code> in <code>set</code>. When I use the following snippet of code</p>
  <pre><code>
   dplyr::group_by(
     record_id,
     voucher_number
   ) %&gt;%
   dplyr::mutate(
     instrument      = row_number(),
     instrument      = replace(instrument, is.na(voucher_number), &quot;application&quot;),
     voucher_sets    = cur_group_id()
   )
      
  </code></pre>
  <p>I am getting the following error:</p>
  <p><code>Error in cur_group_id() : could not find function &quot;cur_group_id&quot;</code></p>
  <p>Any idea what may be going on wrong here. Also the posted dataset is not the true dataset I am working with.</p>