Example configuration for latest Grunt 0.4.4 is missing

I would like to append all cached templates to e.g `dist/scripts/vendor.js`

```
concat: {
app: {
src: ['**.js', '<%= ngtemplates.app.dest %>'],
dest: ['<%= yeoman.dist %>/scripts/vendor.js']
}
},

ngtemplates: {
app: {
src: 'app/views/**/*.html',
dest: 'vendor.js'
}
},
```

Just append not override - as I want to decrease the number of HTTP request, what is the proper configuration to do that?

Some verbose output from `grunt build`

```
Running "concat:app" (concat) task
Verifying property concat.app exists in config...OK
Files: Gruntfile.js, karma-e2e.conf.js, karma.conf.js -> dist/scripts/vendor.js
Options: separator="\n", banner="", footer="", stripBanners=false, process=false
Reading Gruntfile.js...OK
Reading karma-e2e.conf.js...OK
Reading karma.conf.js...OK
Writing dist/scripts/vendor.js...ERROR
Warning: Unable to write "dist/scripts/vendor.js" file (Error code: undefined). Use --force to continue.
```

Tools and versions

```
grunt-cli v0.1.13
grunt v0.4.4
ngtemplates v0.5.4
```