Increase test coverage on `express-map`

Coverage is now at:
```
Statements   : 100% ( 68/68 )
Branches     : 95% ( 38/40 )
Functions    : 100% ( 13/13 )
Lines        : 100% ( 63/63 )
```

I'm having difficulty getting the last two branches, because I can't figure out the use case where they would occur.  How do I obtain a `key` in `routes.keys` that does not have a `name` property?