title: Magento 1 to Magento 2 Migration Tool Issue with No Commands Defined In "Migrate" Namespace
body: <p>When using the Magento Migration Tool, If I run:</p>
  
  <pre><code>php -f bin/magento migrate:data [-r] /vendor/magento/data-migration-tool/etc/ce-to-ce/1.9.2.1/config.xml
  </code></pre>
  
  <p>I get the following Response...</p>
  
  <pre><code> [InvalidArgumentException]                                 
   There are no commands defined in the "migrate" namespace.  
  </code></pre>
  
  <p>I have googled and just found many closed issues and unable to find a solution. Has anyone found a work around for this?</p>
  
  <p>Thanks In advance.</p>