title: can I add a github R package to a local CRAN libraries using miniCRAN
body: <p>I am using <code>miniCRAN</code> to create a local repo and use it on an offline machine.
  I have added the CRAN pacakges that I need and now would like to add an additional package that is only available on github (<code>multidplyr</code> from <a href="https://github.com/tidyverse/multidplyr" rel="nofollow noreferrer">https://github.com/tidyverse/multidplyr</a>).</p>
  
  <p>However, using</p>
  
  <pre><code>addPackage(pkgs = "multidplyr", path = pth, type = c("source"), Rversion = "3.4",
             repos = "https://github.com/tidyverse/multidplyr")
  </code></pre>
  
  <p>gives the error </p>
  
  <pre><code>Warning: unable to access index for repository https://github.com/tidyverse/multidplyr/src/contrib:
    cannot open URL 'https://github.com/tidyverse/multidplyr/src/contrib/PACKAGES'
  </code></pre>
  
  <p>IS there a way to make this work. or any other solution? Should I just get the zip from github and copy as is into the src folder of the local repo?</p>