A prototype API is now out in the class ResourcePackManagerAPI. If your soft-depend on ResourcePackManager you will be able to register a resource pack with this method:
Code (Text):
registerResourcePack(String pluginName,
String path,
boolean encrypts,
boolean distributes,
boolean zips,
boolean local,
String reloadCommand)
Then in the same class you can call reloadResourcePack() which will reload the plugin and apply any changes you sent to the plugin.
Maven:
Code (Text):
<repository>
<id>magmaguy-repo-releases</id>
<name>MagmaGuy's Repository</name>
<url>https://repo.magmaguy.com/releases</url>
</repository>
<dependency>
<groupId>com.magmaguy</groupId>
<artifactId>ResourcePackManager</artifactId>
<version>1.2.0</version>
</dependency>