Add jacoco (#38)

* add denpendencies bom

* add codecov

* add readme
diff --git a/.codecov.yml b/.codecov.yml
new file mode 100644
index 0000000..1acf443
--- /dev/null
+++ b/.codecov.yml
@@ -0,0 +1,6 @@
+coverage:
+  status:
+    # pull-requests only
+    patch:
+      default:
+        threshold: 0.1%
diff --git a/dubbo-cluster-extensions/dubbo-cluster-broadcast-1/Readme.md b/dubbo-cluster-extensions/dubbo-cluster-broadcast-1/Readme.md
new file mode 100644
index 0000000..5adf0e4
--- /dev/null
+++ b/dubbo-cluster-extensions/dubbo-cluster-broadcast-1/Readme.md
@@ -0,0 +1,3 @@
+# Dubbo Cluster BroadCast 1
+
+TBD