title: Unable to install tidyr in R version 3.1.1
body: <p>I am unable to install <code>tidyr</code> package in R version 3.1.1</p>
  
  <p>This is what happens:</p>
  
  <pre><code>install.packages("tidyr")
  
  Installing package into ‘C:/Users/Name/Documents/R/win-library/3.1’
  (as ‘lib’ is unspecified)
  
  Warning in install.packages :
    package ‘tidyr’ is not available (for R version 3.1.1)
  </code></pre>
  
  <p>I have a Windows PC and have just installed <code>dplyr</code> which got installed easily and is running smoothly. </p>
  
  <p>Any ideas why this is happening as this doesn't seem to be a general issue.</p>