title: How to install a package in Julia 1.0 (UndefVarError: Pkg not defined)
body: <p>I installed Julia 1.0, and want to make a simple plot. The first step is to type this on Julia:</p>
  
  <pre><code>Pkg.add("PyPlot")
  </code></pre>
  
  <p>However, an error occurs:</p>
  
  <pre><code>ERROR: UndefVarError: Pkg not defined.
  </code></pre>
  
  <p>The same thing happens when I type: </p>
  
  <pre><code>Pkg.status()
  </code></pre>
  
  <p>What's the best way to install a package in Julia? I use MacOS.</p>