What do you think about initializing issue_continents with a dict comprehension on [line 70](https://github.com/mozilla/mrburns/pull/121/files#diff-7a78994e6046c52624e1652573d96dbaL70) instead of mutating it here?
```python
    issue_continents = {
        issue: [{'continent': cont_code, 'count': 0}
                for cont_code in CONTINENTS]
        for cont_list in data_types.types_map.itervalues()}

```