add dependabot configuration

Author: yeikel

.github/dependabot.yml

@@ -0,0 +1,12 @@
+version: 2
+updates:
+  - package-ecosystem: "maven"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    ignore:
+      - dependency-name: "com.google.guava:guava"
+      - dependency-name: "com.fasterxml.jackson.core:*"
+      - dependency-name: "io.netty:*"
+      - dependency-name: "org.apache.logging.log4j:*"
+      - dependency-name: "org.slf4j:*"