Move the Drupal Devel module from 'required' to 'require-dev'.

The Devel module is a module that provides developer specific debugging functionality. However it should not be run in a production environment, as it can open up exploitable avenues for hacking a site. It should only be enabled and used when doing debugging or development tasks.

The action items for this issue are:

• Move devel from "require" to "require-dev"
• Disable the devel module and export any configuration changes that result.

Note: The devel module can be enabled for local development, which is why it is included in "require-dev".