Added composer file to PHP library

src/php/composer.json

@@ -0,0 +1,15 @@
+{
+  "name": "grpc/grpc",
+  "description": "gRPC library for PHP",
+  "version": "0.2.0",
+  "homepage": "http://grpc.io",
+  "license": "BSD-3-Clause",
+  "require": {
+    "php": ">=5.5.0"
+  },
+  "autoload": {
+    "psr-4": {
+      "Grpc\\": "lib/Grpc/"
+    }
+  }
+}

src/php/composer.lock

@@ -0,0 +1,19 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at http://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "This file is @generated automatically"
+    ],
+    "hash": "65467a098f5fd8b8fe5f7f6e10226f8a",
+    "packages": [],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": [],
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": {
+        "php": ">=5.5.0"
+    },
+    "platform-dev": []
+}