no issue
We weren't being consistent in our use of Mirage's `normalizedRequestAttrs()` method which meant that in certain cases Mirage's internal database had duplicated attrs, the original set being `camelCase` and the new/updated set being `underscore_case` which was not only confusing but can lead to errors or unexpected behaviour in tests.
- updated Mirage config to always normalize where necessary
- updated tests to always use `camelCase` attrs
- added `HEAD` route handler for gravatar to avoid unknown route noise in tests
