Fix incorrect result type of the chat report api

Author: rubengees

library/src/main/java/me/proxer/library/api/chat/InternalApi.java

@@ -36,8 +36,8 @@ ProxerCall<String> sendMessage(@Field("room_id") String roomId,
 
     @FormUrlEncoded
     @POST("chat/reportmessage")
-    ProxerCall<String> reportMessage(@Field("message_id") String messageId,
-                                     @Field("message") String message);
+    ProxerCall<Void> reportMessage(@Field("message_id") String messageId,
+                                   @Field("message") String message);
 
     @GET("chat/roomusers")
     ProxerCall<List<ChatRoomUser>> roomUsers(@Query("room_id") String roomId);

library/src/main/java/me/proxer/library/api/chat/ReportChatMessageEndpoint.java

@@ -10,7 +10,7 @@
  * @author Ruben Gees
  */
 @Accessors(fluent = true)
-public final class ReportChatMessageEndpoint implements Endpoint<String> {
+public final class ReportChatMessageEndpoint implements Endpoint<Void> {
 
     private final InternalApi internalApi;
 
@@ -27,7 +27,7 @@ public final class ReportChatMessageEndpoint implements Endpoint<String> {
      * {@inheritDoc}
      */
     @Override
-    public ProxerCall<String> build() {
+    public ProxerCall<Void> build() {
         return internalApi.reportMessage(messageId, message);
     }
 }

library/src/test/java/me/proxer/library/api/chat/ReportChatMessageEndpointTest.java

@@ -18,7 +18,7 @@ public class ReportChatMessageEndpointTest extends ProxerTest {
     public void testDefault() throws ProxerException, IOException {
         server.enqueue(new MockResponse().setBody(fromResource("empty.json")));
 
-        final String result = api.chat()
+        final Void result = api.chat()
                 .reportMessage("123", "message")
                 .build()
                 .execute();