add server pinger

src/main/java/cc.fascinated/model/cache/CachedMinecraftServer.java

@@ -0,0 +1,31 @@
+package cc.fascinated.model.cache;
+
+import cc.fascinated.model.server.MinecraftServer;
+import lombok.*;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.redis.core.RedisHash;
+
+import java.io.Serializable;
+
+/**
+ * @author Braydon
+ */
+@AllArgsConstructor @Setter @Getter @ToString
+@RedisHash(value = "server", timeToLive = 60L) // 1 minute (in seconds)
+public final class CachedMinecraftServer implements Serializable {
+    /**
+     * The id of this cached server.
+     */
+    @Id @NonNull private transient final String id;
+
+    /**
+     * The cached server.
+     */
+    @NonNull private final MinecraftServer value;
+
+    /**
+     * The unix timestamp of when this
+     * server was cached, -1 if not cached.
+     */
+    private long cached;
+}