Limit supported configurations to node >= 2.4.0.

We use C++11 features, which versions of node before 1.8.4 don't seem
to support (at least not with their default compiler options).

We also use `v8::NativeWeakMap`, which was introduced in the 2.4.0 ABI.
This could probably be worked around (see the node-1.8.4 branch in
github), but it doesn't seem worth it right now.

Author: cscott

.travis.yml

@@ -49,22 +49,11 @@ matrix:
        env: NODE_VERSION="iojs-2.4.0" PUBLISHABLE=false
      - os: linux
        env: NODE_VERSION="iojs-2.4.0" BUILD_X86=true # node abi 44
-     - os: linux
-       compiler: clang
-       env: NODE_VERSION="iojs-1.8.4" PUBLISHABLE=false
-     - os: linux
-       env: NODE_VERSION="iojs-1.8.4" BUILD_X86=true # node abi 43
-     - os: linux
-       env: NODE_VERSION="0.12.7" BUILD_X86=true # node abi 14
-     - os: linux
-       env: NODE_VERSION="0.10.40" BUILD_X86=true # node abi 11
-     - os: linux
-       env: NODE_VERSION="0.8.28" BUILD_X86=true # node abi 1
 # disabled because libphp5-embed package is not on whitelist yet
 # https://github.com/travis-ci/apt-package-whitelist#package-approval-process
 #     # test building against external libphp5
 #     - os: linux
-#       env: NODE_VERSION="4.1.1" EXTERNAL_LIBPHP=true PUBLISHABLE=false
+#       env: NODE_VERSION="4.1.2" EXTERNAL_LIBPHP=true PUBLISHABLE=false
 #       addons:
 #         apt:
 #            sources: [ 'libphp5-embed:i386', 'php5-dev:i386' ]
@@ -79,18 +68,6 @@ matrix:
      - os: osx
        compiler: clang
        env: NODE_VERSION="iojs-2.4.0" # node abi 44
-     - os: osx
-       compiler: clang
-       env: NODE_VERSION="iojs-1.8.4" # node abi 43
-     - os: osx
-       compiler: clang
-       env: NODE_VERSION="0.12.7" # node abi 14
-     - os: osx
-       compiler: clang
-       env: NODE_VERSION="0.10.40" # node abi 11
-     - os: osx
-       compiler: clang
-       env: NODE_VERSION="0.8.28" # node abi 1
 
 before_install:
 - export PUBLISHABLE=${PUBLISHABLE:-true}

README.md

@@ -6,6 +6,10 @@
 The node `php-embed` package binds to PHP's "embed SAPI" in order to
 provide interoperability between PHP and JavaScript code.
 
+Node/iojs >= 2.4.0 is currently required, since we use `NativeWeakMap`s
+in the implementation.  This could probably be worked around using
+v8 hidden properties, but it doesn't seem worth it right now.
+
 # USAGE
 
 ```js

package.json

@@ -29,6 +29,7 @@
     "host": "https://github.com",
     "remote_path": "/cscott/node-php-embed/releases/download/{version}/"
   },
+  "engines" : { "node" : ">=2.4.0" },
   "dependencies": {
     "nan": "~2.1.0",
     "node-pre-gyp": "~0.6.11",