Merge branch '1.X': Bumped to 2.2.X for engines >=4

Author: nmccready

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gulp-sourcemaps",
-  "version": "2.1.1",
+  "version": "2.2.0",
   "description": "Source map support for Gulp.js",
   "homepage": "http://github.com/floridoo/gulp-sourcemaps",
   "repository": "git://github.com/floridoo/gulp-sourcemaps.git",
@@ -42,5 +42,8 @@
   "files": [
     "index.js",
     "src"
-  ]
+  ],
+  "engines": {
+    "node": ">=4"
+  }
 }