Add playing state

src/main/java/wtf/beatrice/hidekobot/HidekoBot.java

@@ -2,6 +2,7 @@ package wtf.beatrice.hidekobot;
 
 import net.dv8tion.jda.api.JDA;
 import net.dv8tion.jda.api.JDABuilder;
+import net.dv8tion.jda.api.entities.Activity;
 import wtf.beatrice.hidekobot.utils.Logger;
 
 import javax.security.auth.login.LoginException;
@@ -12,13 +13,20 @@ public class HidekoBot
 
     public static void main(String[] args)
     {
+        JDABuilder jdaBuilder;
+        JDA jda;
+
         try
         {
-            JDA jda = JDABuilder.createDefault("").build();
+            jdaBuilder = JDABuilder.createDefault("");
+            jdaBuilder.setActivity(Activity.playing("the piano"));
+            jda = jdaBuilder.build();
         } catch (LoginException e)
         {
             logger.log(e.getMessage());
-        }
+            return;
+        }
+
     }
 
 }