Merge the matrix-java-sdk due to it no longer maintained. Remove thirdparty repositories.

src/main/java/io/kamax/matrix/event/_MatrixEvent.java

@@ -0,0 +1,32 @@
+/*
+ * matrix-java-sdk - Matrix Client SDK for Java
+ * Copyright (C) 2018 Arne Augenstein
+ *
+ * https://www.kamax.io/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package io.kamax.matrix.event;
+
+import com.google.gson.JsonObject;
+
+public interface _MatrixEvent {
+
+    String getType();
+
+    JsonObject getJson();
+
+}