title: Unable to run two migration execute commands together within a single console command
body: <p>For development we have a single Symfony console command that executes other console commands in order to rebuild db, run fixtures etc.</p>
  
  <p>As part of the process I need to run a few cherry-picked doctrine migration commands, but for some reason I'm unable to run multiple execute commands within the same process.</p>
  
  <p>To confirm, I can run these tasks without issue manually, and can run one of either command within the console execute and then the other manually without issue.</p>
  
  <pre><code>          $this-&gt;getApplication()-&gt;run(new ArrayInput(array(
              'command' =&gt; 'doctrine:migrations:execute',
              'version' =&gt; '20140310162336',
                '--no-interaction' =&gt; true
                  )), $output);
  
            $this-&gt;getApplication()-&gt;run(new ArrayInput(array(
              'command' =&gt; 'doctrine:migrations:execute',
              'version' =&gt; '20140310170437',
                '--no-interaction' =&gt; true
                  )), $output);
  </code></pre>
  
  <p>The error returned is:</p>
  
  <pre><code>[Doctrine\DBAL\Migrations\MigrationException]
  Migration version 20140310162334 already registered with class Doctrine\DBAL\Migrations\Version
  </code></pre>
  
  <p>The version being the first version file that exists, can confirm that one is not in the migration_versions table, nor is it wanted in this scenario. Suggesting it is just loaded into the migrations object.</p>
  
  <p>Can anyone offer input if I'm doing something wrong of if this is perhaps a bug somewhere.</p>
  
  <p>Running Symfony 2.2.* and migrations bundle using dev-master.</p>