title: Remove legend from rChart
body: <p>I am using rCharts library in a Shiny application and want to remove the right side legend.</p>
  
  <p>The tips I found did not work in this case... 
  for example: <code>p1$chart(showLegend = FALSE)</code></p>
  
  <p><strong>My code is similar to this one:</strong></p>
  
  <pre><code>library(rCharts)
  
  mydata&lt;-data.frame(weekday=c("friday","monday","thursday","tuesday","saturday","sunday","wednesday"),value=rnorm(7,10,2))
  
  
  p1&lt;-rPlot(value ~ weekday, color = 'weekday', data = mydata, type = 'bar')
  
    p1$guides(
      color = list(
        numticks = length(unique(mydata$weekday))
      ),
      x = list(title="",
               ticks = c('sunday', 'monday', 'tuesday','wednesday','thursday','friday','saturday'),
               labels ="",
               levels = c('sunday', 'monday', 'tuesday','wednesday','thursday','friday','saturday')
      ),
      y = list(title=""
      )
    )
  
  
    p1$chart(showLegend = FALSE)
  
  p1
  </code></pre>