configs for runtime-docker-1.15.0 and runtime-java-1.18.0 (#421)

diff --git a/release-configs/runtime-docker-1.15.0.config b/release-configs/runtime-docker-1.15.0.config
new file mode 100644
index 0000000..34f6708
--- /dev/null
+++ b/release-configs/runtime-docker-1.15.0.config
@@ -0,0 +1,15 @@
+{
+  "versioning": {
+    "version": "1.15.0",
+    "pre_release_version": "rc1"
+  },
+  "RepoList": [
+    "openwhisk-runtime-docker"
+  ],
+  "openwhisk_runtime_docker": {
+    "name": "OpenWhisk Runtime Docker",
+    "hash": "1d8a6edb4ee7e4883a2f94d6fbc5fc0d330bb26b",
+    "repository": "https://github.com/apache/openwhisk-runtime-docker.git",
+    "branch": "master"
+  }
+}
diff --git a/release-configs/runtime-java-1.18.0.config b/release-configs/runtime-java-1.18.0.config
new file mode 100644
index 0000000..07f3107
--- /dev/null
+++ b/release-configs/runtime-java-1.18.0.config
@@ -0,0 +1,15 @@
+{
+  "versioning": {
+    "version": "1.18.0",
+    "pre_release_version": "rc1"
+  },
+  "RepoList": [
+    "openwhisk-runtime-java"
+  ],
+  "openwhisk_runtime_java": {
+    "name": "OpenWhisk Runtime Java",
+    "hash": "725d6c40eea775d95f47073b92322bdd8f42ea6e",
+    "repository": "https://github.com/apache/openwhisk-runtime-java.git",
+    "branch": "master"
+  }
+}