php: remove explicit version in composer.json

composer.json

@@ -2,7 +2,6 @@
   "name": "grpc/grpc",
   "type": "library",
   "description": "gRPC library for PHP",
-  "version": "0.15.0",
   "keywords": ["rpc"],
   "homepage": "http://grpc.io",
   "license": "BSD-3-Clause",

templates/composer.json.template

@@ -4,7 +4,6 @@
     "name": "grpc/grpc",
     "type": "library",
     "description": "gRPC library for PHP",
-    "version": "${settings.php_version.php()}",
     "keywords": ["rpc"],
     "homepage": "http://grpc.io",
     "license": "BSD-3-Clause",