[Bug] Local files not found when using exposurelib_tests

We are using exposurelib_tests to setup a similar testing pipeline in EntityInitializer.

When we do that, we get the error:

ERROR tests/test_spatialite.py::TestSpatiaLiteExposureBase::test_database_connection - FileNotFoundError:
[Errno 2] No such file or directory: 'exposurelib_tests/fixtures/boundaries.txt'

These files need to be copied when exposurelib_tests is installed to not have this issue.