Added latest Guava and SLF4J compatibility

(1.18+ breaks support to older guava methods)

core/pom.xml

@@ -74,14 +74,14 @@
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-jdk14</artifactId>
-            <version>1.7.32</version>
+            <version>2.0.0-alpha5</version>
         </dependency>
 
         <!-- snakeyaml is present in Bungee, Spigot, Cauldron and so we could use this independent implementation -->
         <dependency>
             <groupId>net.md-5</groupId>
             <artifactId>bungeecord-config</artifactId>
-            <version>1.12-SNAPSHOT</version>
+            <version>1.16-R0.4</version>
             <exclusions>
                 <exclusion>
                     <groupId>*</groupId>
@@ -117,14 +117,26 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>17.0</version>
+            <version>31.0.1-jre</version>
             <scope>provided</scope>
         </dependency>
 
         <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>
-            <version>2.2.4</version>
+            <version>2.8.9</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>2.0.0-alpha5</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-simple</artifactId>
+            <version>2.0.0-alpha5</version>
+            <scope>runtime</scope>
         </dependency>
     </dependencies>
 </project>