Add gson to dependency management

cache/pom.xml

@@ -65,7 +65,6 @@
 		<dependency>
 			<groupId>com.google.code.gson</groupId>
 			<artifactId>gson</artifactId>
-			<version>2.4</version>
 		</dependency>
 		<dependency>
 			<groupId>io.netty</groupId>

http-api/pom.xml

@@ -43,7 +43,6 @@
 		<dependency>
 			<groupId>com.google.code.gson</groupId>
 			<artifactId>gson</artifactId>
-			<version>2.4</version>
 		</dependency>
 		<dependency>
 			<groupId>org.slf4j</groupId>

pom.xml

@@ -142,6 +142,11 @@
 				<version>${lombok.version}</version>
 				<scope>provided</scope>
 			</dependency>
+			<dependency>
+				<groupId>com.google.code.gson</groupId>
+				<artifactId>gson</artifactId>
+				<version>2.4</version>
+			</dependency>
 		</dependencies>
 	</dependencyManagement>
 

runelite-client/pom.xml

@@ -72,7 +72,6 @@
 		<dependency>
 			<groupId>com.google.code.gson</groupId>
 			<artifactId>gson</artifactId>
-			<version>2.4</version>
 		</dependency>
 		<dependency>
 			<groupId>net.runelite.pushingpixels</groupId>