Description

I see many copies of conftest.py files buried in the package. The most troubling are astropy/conftest.py and conftest.py that contain duplicated code.

1. astropy/coordinates/tests/conftest.py
2. astropy/table/tests/conftest.py
3. astropy/wcs/tests/conftest.py
4. astropy/wcs/wcsapi/conftest.py
5. astropy/conftest.py
6. docs/conftest.py
7. conftest.py

Expected behavior

One and only one conftest.py at root directory.

Proposed solution

• Move stuff from lower level conftest.py files to the root level one. Eliminated duplicate code.
• Move subpackage specfici test helper functions into subpackage/tests/utils.py if they are not needed at the root conftest.py level.

Need to know

• Is there a reason why proposed solution above wouldn't work?