package: remove the "preinstall" phase, add the "test" phase

package.json

@@ -6,7 +6,7 @@
  , "homepage": "https://github.com/learnboost/node-canvas"
  , "repository": "git://github.com/learnboost/node-canvas"
  , "scripts": {
-   "preinstall": "node-waf configure build"
+   "test": "make test"
  }
  , "devDependencies": {
      "express": ">= 2.3.7 && < 3.0.0"
@@ -16,4 +16,4 @@
  }
  , "engines": { "node": ">= 0.4.0 && < 0.9.0" }
  , "main": "./lib/canvas.js"
-}
+}