Added npm packaging option

Gruntfile.js

@@ -0,0 +1,45 @@
+module.exports = function(grunt) {
+
+  // Project configuration.
+  grunt.initConfig({
+    clean: {
+      build: ["build"]
+    },
+    exec: {
+      npm_pack: {
+        cmd: 'npm pack ./package',
+        cwd: 'build/'
+      },
+	  gradle: 'gradle build'
+    },
+    copy: {
+      package: {
+        files: [
+          { expand: true, src: 'package.json', dest: 'build/package' },
+		  { expand: true, cwd: 'widgets/build/outputs/aar', src: 'widgets-release.aar', dest: 'build/package/platforms/android' }
+        ]
+      }
+    },
+    mkdir: {
+      build: {
+        options: {
+          create: ["build/package"]
+        }
+      }
+    }
+  });
+
+  grunt.loadNpmTasks('grunt-exec');
+  grunt.loadNpmTasks('grunt-contrib-copy');
+  grunt.loadNpmTasks('grunt-contrib-clean');
+  grunt.loadNpmTasks('grunt-mkdir');
+
+  // Default task(s).
+  grunt.registerTask('default', [
+    'clean:build',
+    'mkdir:build',
+	'exec:gradle',
+    'copy:package',
+    'exec:npm_pack'
+  ]);
+};