title: Installing a react native package with Podfile
body: <p>I'm following instructions here to add a package: https://github.com/joltup/rn-fetch-blob
  It says to do npm install OR add to Podfile. What I did was</p>
  <p><code>yarn add rn-fetch-blob</code></p>
  <p>Then </p>
  <pre><code>cd ios
  pod install
  </code></pre>
  <p>Is that correct? I didn't edit the Podfile but somehow it still knew to get the dependency. Output:</p>
  <pre><code>Analyzing dependencies
  Downloading dependencies
  Installing rn-fetch-blob (0.12.0)
  Generating Pods project
  Integrating client project
  </code></pre>
  <p>The Podfile doesn't have any reference to rn-fetch-blob. Can someone explain if I did it right or if I needed to edit the Podfile?</p>