add server pinger

src/main/java/cc.fascinated/model/mojang/MojangUsernameToUuid.java

@@ -0,0 +1,27 @@
+package cc.fascinated.model.mojang;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter @NoArgsConstructor
+public class MojangUsernameToUuid {
+
+    /**
+     * The UUID of the player.
+     */
+    private String id;
+
+    /**
+     * The name of the player.
+     */
+    private String name;
+
+    /**
+     * Check if the profile is valid.
+     *
+     * @return if the profile is valid
+     */
+    public boolean isValid() {
+        return id != null && name != null;
+    }
+}