Update Aquatic description and fix hierarchy (#2551)

* Update Aquatic description and fix hierarchy

* run spotlessApply

Author: ImMorpheus

src/main/java/org/spongepowered/api/entity/living/aquatic/Aquatic.java

@@ -24,11 +24,10 @@
  */
 package org.spongepowered.api.entity.living.aquatic;
 
-import org.spongepowered.api.block.BlockTypes;
 import org.spongepowered.api.entity.living.PathfinderAgent;
 
 /**
- * Represents an aquatic creature that may be found in {@link BlockTypes#WATER}
+ * Represents an aquatic creature that needs to stay in water to survive
  */
 public interface Aquatic extends PathfinderAgent {
 

src/main/java/org/spongepowered/api/entity/living/monster/guardian/Guardian.java

@@ -28,14 +28,13 @@
 import org.spongepowered.api.data.value.Value;
 import org.spongepowered.api.entity.living.Living;
 import org.spongepowered.api.entity.living.Monster;
-import org.spongepowered.api.entity.living.aquatic.Aquatic;
 
 import java.util.Optional;
 
 /**
  * Represents a Guardian.
  */
-public interface Guardian extends Aquatic, Monster {
+public interface Guardian extends Monster {
 
     /**
      * {@link Keys#BEAM_TARGET_ENTITY}