title: bundle uses wrong ruby version
body: <p>I'm trying to run </p>
  
  <p><code>env RAILS_ENV=test bundle exec rake db:migrate</code></p>
  
  <p>and get the following error </p>
  
  <p><code>Your Ruby version is 2.1.7, but your Gemfile specified 2.2.3</code></p>
  
  <p><code>ruby -v</code> </p>
  
  <p>gives me</p>
  
  <p><code>ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-darwin15]</code></p>
  
  <p>I'm using rbenv, if that matters. <code>rbenv versions</code> gives the following:
  <code>
    system
  * 2.2.3 (set by /Users/thatsme/Projects/demoproject/.ruby-version)
  </code>
  So I have no <code>ruby 2.1.7</code> installed. Spring is not running and I've run <code>rbenv rehash</code>. Then <code>bundler gem</code> is installed.
  I'm going nuts on this. Can somebody please tell me why the wrong ruby version is being used? Thanks!</p>