title: Two Ruby versions simultaneously?
body: <p>I don't seem to be able to consistently switch between Ruby versions using rvm.  Having many gem issues--for example:</p>
  
  <pre><code>capybara-3.26.0 requires ruby version &gt;= 2.4.0, which is incompatible with the current version, ruby 2.3.3p222
  [10:27:12] (master)
  // ruby -v
  ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-darwin17]
  [10:27:13] (master)
  // rvm list
     ruby-2.3.3 [ x86_64 ]
  =* ruby-2.6.0 [ x86_64 ]
     ruby-2.6.1 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  </code></pre>
  
  <p>I get alternating messages that I'm using one but need the other.  I don't care which I use so long as it works.</p>
  
  <p>Even after <code>rvm uninstall 2.3.3</code> I still get that I'm using 2.3.3 when trying to run <code>bundle</code></p>