This is needed to avoid a "test race" and get it closer to a real unit
test.
When running it along with others it passes:
```
$ make test-unit
...
48 passing (54ms)
12 pending
```
(note it relies on the ordering produced by `find`)
when running it along with some other test that reads the config, it
works as well:
```
$ test/run_tests.sh test/unit/apikeyauth.test.js test/unit/error_handler.test.js
...
3 passing (9ms)
12 pending
```
but when run in isolation, it fails:
```
$ test/run_tests.sh test/unit/error_handler.test.js
...
0 passing (15ms)
3 failing
1) error-handler should return a header with errors:
TypeError: Cannot read property 'environment' of undefined
at errorMiddleware (app/middlewares/error.js:10:28)
at Context.<anonymous> (test/unit/error_handler.test.js:53:26)
2) error-handler JSONP should return a header with error statuscode:
TypeError: Cannot read property 'environment' of undefined
at errorMiddleware (app/middlewares/error.js:10:28)
at Context.<anonymous> (test/unit/error_handler.test.js:79:26)
3) error-handler should escape chars that broke logs regex:
TypeError: Cannot read property 'environment' of undefined
at errorMiddleware (app/middlewares/error.js:10:28)
at Context.<anonymous> (test/unit/error_handler.test.js:108:26)
```
