title: R - plotly - hide colorbar
body: <p>How can I hide the colorbar in the following plotly example taken from their website? </p>
  
  <pre><code>    df &lt;- read.csv('https://raw.githubusercontent.com/plotly/datasets/master/2014_world_gdp_with_codes.csv')
  
  # light grey boundaries
  l &lt;- list(color = toRGB("grey"), width = 0.5)
  
  # specify map projection/options
  g &lt;- list(
    showframe = FALSE,
    showcoastlines = FALSE,
    projection = list(type = 'Mercator')
  )
  
  plot_ly(df, z = GDP..BILLIONS., text = COUNTRY, locations = CODE, type = 'choropleth',
          color = GDP..BILLIONS., colors = 'Blues', marker = list(line = l),
          colorbar = list(tickprefix = '$', title = 'GDP Billions US$'),
          filename="r-docs/world-choropleth") %&gt;%
    layout(title = '2014 Global GDP&lt;br&gt;Source:&lt;a href="https://www.cia.gov/library/publications/the-world-factbook/fields/2195.html"&gt;CIA World Factbook&lt;/a&gt;',
           geo = g)
  </code></pre>
  
  <p>The figure reference does not provide an answer: <a href="https://plot.ly/r/reference/#colorbar" rel="noreferrer">https://plot.ly/r/reference/#colorbar</a>. I can hide the colorbar via editing the graph, but I would like to control this in the R code. </p>