Users should be able to load arbitrary connector classes

[hyfen]

Ways this could work:

• using --extractor ./custom_extractor.rb as a flag
• a known plugin directory in the config directory

We take that file, attempt to load it (and rescue from LoadError), and then set it as the connector in the JobDefinition.

This system would also need

• basic validation system to ensure the right things are required and included

Limitations:

• doesn't handle dependency management