title: ESLint's "no-undef" rule is calling my use of Underscore an undefined variable
body: <p>I am using Grunt as my Build Tool and ESLint as my linting tool for an app I am working on. I am also using the Underscore Node package, and have made use of it in my app. Unfortunately, when I run ESLint on my code, it thinks that _ is an undefined variable in the following line:</p>
  
  <p><code>return _.pluck(objects, nameColumn);</code></p>
  
  <p>This is the error it is giving me:</p>
  
  <p><code>78:21  error  "_" is not defined  no-undef</code></p>
  
  <p>I would prefer not to disable the no-undef rule for ESLint, and I have tried installing the Underscore plugin, but I am still receiving this error. If anyone else has any ideas for what to try with this, I would be very appreciative!</p>
  
  <p>If there is any further information I can give that would help anyone with helping me get this figured out, just let me know!</p>