create base email tests for activesync and add tests for outlook coverage

To address https://github.com/mozilla/gaia-ui-tests/issues/1251.

To run these tests, you will have to add the following test variables to your existing test vars file under `ActiveSync`.

```
    "Outlook":{
      "name": "Mozilla WebQA User",
      "email": "mozwebqa.outlook@outlook.com",
      "password": "Sparky2013",
      "active_sync_hostname": "m.hotmail.com",
      "active_sync_username": "mozwebqa.outlook@outlook.com"
    }
```