Document openwhisk-runtime-php 1.16.0 (#370)

diff --git a/release-configs/runtime-php-1.16.0.config b/release-configs/runtime-php-1.16.0.config
new file mode 100644
index 0000000..4819de3
--- /dev/null
+++ b/release-configs/runtime-php-1.16.0.config
@@ -0,0 +1,15 @@
+{
+  "versioning": {
+    "version": "1.16.0",
+    "pre_release_version": "rc1"
+  },
+  "RepoList": [
+    "openwhisk-runtime-php"
+  ],
+  "openwhisk_runtime_php": {
+    "name": "OpenWhisk Runtime PHP",
+    "hash": "13018ac27754a7df7c00929d1f3b7701cbee4d36",
+    "repository": "https://github.com/apache/openwhisk-runtime-php.git",
+    "branch": "master"
+  }
+}