Add paper specific listener for entity loading

pom.xml

@@ -90,6 +90,11 @@
             <artifactId>spigot</artifactId>
             <version>1.15-R0.1-SNAPSHOT</version>
         </dependency>
+        <dependency>
+            <groupId>org.spigotmc</groupId>
+            <artifactId>spigot</artifactId>
+            <version>1.15-R0.1-SNAPSHOT</version>
+        </dependency>
         <!-- testing -->
         <dependency>
             <groupId>junit</groupId>
@@ -97,6 +102,12 @@
             <version>4.12</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.destroystokyo.paper</groupId>
+            <artifactId>paper-api</artifactId>
+            <version>1.15.2-R0.1-SNAPSHOT</version>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 
     <repositories>
@@ -112,6 +123,10 @@
             <id>spigot-repo</id>
             <url>https://hub.spigotmc.org/nexus/content/repositories/snapshots/</url>
         </repository>
+        <repository>
+            <id>papermc</id>
+            <url>https://papermc.io/repo/repository/maven-public/</url>
+        </repository>
     </repositories>
 
     <distributionManagement>