title: File error when running a simple read.csv command in R
body: <p>When I run <code>read.csv</code> <a href="http://raw.githubusercontent.com/genomicsclass/dagdata/master/inst/extdata/msleep_ggplot2.csv" rel="nofollow noreferrer">on a dataset</a></p>
  
  <pre><code>read.csv(file = msleep_ggplot2, header = TRUE, sep = ",")
  </code></pre>
  
  <p>I get an error message:</p>
  
  <blockquote>
    <p>Error in read.table(file = file, header = header, sep = sep, quote = quote, : 'file' must be a character string or connection</p>
  </blockquote>
  
  <p>The <code>csv</code> file loaded in r studio and looks good. Any idea what the problem might be?</p>