deploy/test-oas/plugins

The expected structure is as follows: the given plugins root folder,
containing the plugins folder. One plugin folder contains all
resources (jar files) belonging to a plugin. The name of the plugin
folder becomes the plugin id. For example:

plugins/ (root folder)
|------------plugin-a/ (folder of plugin a)
| |-plugin-a-1.jar
| |-plugin-a-2.jar
| |-...
| |-(the jars containing the classes of plugin a)
|
|------------plugin-b/
| |-plugin-b-1.jar
| |-...
...

Read more in the documentation about how to create a plugin.