Don't include guava in the jar & go for lower version for bukkit compatibility

pom.xml

@@ -111,7 +111,8 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>19.0</version>
+            <version>17.0</version>
+            <scope>provided</scope>
         </dependency>
     </dependencies>