title: rake task that writes to file on local filesystem and not heroku
body: <p>I would like a rake task that gets some information and then writes to the local filesytem</p>
  
  <p>I thought I had this working but not sure how. </p>
  
  <pre><code>namespace :arc do
    task :vday =&gt; :environment do
      locations=Location.with_current_mec "something"
      jt={}
      jt[:locations]={}
      locations.each do |location|
        jt[:locations][location.id]=location.to_small_hash
      end
      # want this to write to local filesytem
      File.write('/Users/jt/output.json', JSON.pretty_generate(jt))
    end
  end
  </code></pre>
  
  <p>and then call like </p>
  
  <pre><code>heroku run rake arc:vday
  </code></pre>
  
  <p>But this is not working and gives me an error on writing the file. Is there a workaround to make it write to my local filesystem and not heroku? </p>