Add test for department handling

Description
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The unity js scopes package have a minimal set of tests associated with a few of the features exposed in the JS scopes api. Those tests need to be expanded.

This bug aims at adding a new test for the Scopes Department feature.

Technical context
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Scopes are a fundamental piece of the UbuntuTouch user experience. Each scope offers user driven way to interact with one of more sources of either local or remote data displayed in a uniform fashion from the Ubuntu Dash.

https://developer.ubuntu.com/en/scopes/guides/scopes-guide/

The Unity Scopes API allows developers to create scopes in C++.

https://developer.ubuntu.com/api/devel/ubuntu-14.10/cplusplus/unity-scopes/index.html

Unity JS scopes is a package that enables the creation of Javascript Scopes by offering bindings of the Unity Scopes API in Javascript.

In order to get started with the unity-js-scopes package, you can have a look at the README file found at the top of the package's sources:

http://bazaar.launchpad.net/~webapps/unity-js-scopes/trunk/view/head:/README.md

In the context of the API, Departments are ways to group results from a search in various top level groups

https://developer.ubuntu.com/api/devel/ubuntu-14.10/cplusplus/unity-scopes/classunity_1_1scopes_1_1_department.html

Examples of department usage can be found in one of the sample scope provided by the unity-js-scopes package:

http://bazaar.launchpad.net/~webapps/unity-js-scopes/trunk/view/head:/examples/simple/simple.js#L125

Existing tests for some parts of the scopes API can be found here:

http://bazaar.launchpad.net/~webapps/unity-js-scopes/trunk/files/head:/tests/owm_scope/

The tests can be run with:

make test

Each tests contains a server part that feeds the desired data to the scope and the js scope itself

Deliverable
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Add a test for department handling that tests the same functionalities found in the simple.js scope above and validates that no issues occur.