title: Atom linter-lintr cannot find lintr
body: <p>I am using Atom for writing R code, and attempting to use lintr, but linter-lintr cannot find it. R is on my <code>$PATH</code> and <code>lintr</code> is installed in R.</p>
  
  <p>Whenever I type, the following error happens.</p>
  
  <pre><code>/Users/bfh/.atom/packages/linter/lib/linter-registry.js:159 [Linter] Error running lintr Error: Error in library(lintr) : there is no package called 'lintr'
  Calls: suppressPackageStartupMessages -&gt; withCallingHandlers -&gt; library
  Execution halted
      at ChildProcess.&lt;anonymous&gt; (/Users/bfh/.atom/packages/linter-lintr/node_modules/sb-exec/lib/index.js:56:20)
      at emitTwo (events.js:106:13)
      at ChildProcess.emit (events.js:191:7)
      at maybeClose (internal/child_process.js:877:16)
      at Process.ChildProcess._handle.onexit (internal/child_process.js:226:5)(anonymous function) @ /Users/bfh/.atom/packages/linter/lib/linter-registry.js:159
  </code></pre>
  
  <p>I have tried uninstalling and reinstalling linter, linter-lintr, linter-minimap, and the relevant R packages. This setup is working fine on another computer.</p>