Warnings/logging messages when importing sub-packages

[saimn]

Ref astropy/astropy#10893.
Importing all astroquery sub-packages raises a bunch of warning and logging messages:

/home/simon/.pyenv/versions/3.8.1/lib/python3.8/site-packages/astroquery/alfalfa/__init__.py:15: UserWarning: Experimental: ALFALFA has not yet been refactored to have its API match the rest of astroquery.
  warnings.warn("Experimental: ALFALFA has not yet been refactored to have "
WARNING: Astrometry.net API key not found in configuration file [astroquery.astrometry_net.core]
WARNING: You need to manually edit the configuration file and add it [astroquery.astrometry_net.core]
WARNING: You may also register it for this session with AstrometryNet.key = 'XXXXXXXX' [astroquery.astrometry_net.core]
Please install pyvo. astropy.cadc does not work without it.
Could not import mocpy, which is a requirement for the CDS service.Please refer to https://cds-astro.github.io/mocpy/install.html for how to install it.
Could not import astropy-regions, which is a requirement for the CDS service.Please refer to http://astropy-regions.readthedocs.io/en/latest/installation.html for how to install it.
Created TAP+ (v1.2.1) - Connection:
	Host: hst.esac.esa.int
	Use HTTPS: False
	Port: 80
	SSL Port: 443
Created TAP+ (v1.2.1) - Connection:
	Host: nxsa.esac.esa.int
	Use HTTPS: False
	Port: 80
	SSL Port: 443
/home/simon/.pyenv/versions/3.8.1/lib/python3.8/site-packages/astroquery/fermi/__init__.py:37: UserWarning: Experimental: Fermi-LAT has not yet been refactored to have its API match the rest of astroquery.
  warnings.warn("Experimental: Fermi-LAT has not yet been refactored to have "
Created TAP+ (v1.2.1) - Connection:
	Host: gea.esac.esa.int
	Use HTTPS: True
	Port: 443
	SSL Port: 443
Created TAP+ (v1.2.1) - Connection:
	Host: geadata.esac.esa.int
	Use HTTPS: True
	Port: 443
	SSL Port: 443
/home/simon/.pyenv/versions/3.8.1/lib/python3.8/site-packages/astroquery/lcogt/__init__.py:12: UserWarning: The LCOGT archive API has been changed. While we aim to accommodate the changes into astroqeury, pleased be advised that this module is not working at the moment.
  warnings.warn("The LCOGT archive API has been changed. While we aim to "
/home/simon/.pyenv/versions/3.8.1/lib/python3.8/site-packages/astroquery/ogle/__init__.py:40: UserWarning: Experimental: OGLE has not yet been refactored to have its API match the rest of astroquery.
  warnings.warn("Experimental: OGLE has not yet been refactored to have its "
/home/simon/.pyenv/versions/3.8.1/lib/python3.8/site-packages/astroquery/sha/__init__.py:14: UserWarning: Experimental: SHA has not yet been refactored to have its API match the rest of astroquery.
  warnings.warn("Experimental: SHA has not yet been refactored to have its "
/home/simon/.pyenv/versions/3.8.1/lib/python3.8/site-packages/astroquery/vamdc/core.py:112: UserWarning: vamdclib could not be imported; the vamdc astroquery module will not work
  warnings.warn("vamdclib could not be imported; the vamdc astroquery module "
Could not import regions, which is required for some of the functionalities of this module.

[bsipocz]

Of these some are on the radar, and some I think should stay:

• Default to verbose=False upon TapPlus instantiation #1722 is about turning off the TAP info.
• the import warnings are better kept, but the pyvo one can be turned to an error as pyvo is now a mandatory dependency
• we should delete the lcogt module rather than issuing the warning
• maybe we need to reconsider the alfaalfa, sha, ogle warnings about the refactoring, it is not very useful for the user

[bsipocz]

@saimn - you mentioned some deprecations, are any of those relevant for astroquery? (pyregions and html5lib ones are ignored, but all the rest should be dealt with)

[saimn]

No sorry, I meant taht generate_config already filters deprecation warnings, but it seems that there are no such warning for astroquery. Btw to reproduce and import all sub-packages:

In [1]: import pkgutil, importlib, astroquery
   ...: for mod in pkgutil.walk_packages(astroquery.__path__, prefix='astroquery.'):
   ...:     importlib.import_module(mod.name)

[bsipocz]

Some things got cleaned up, and all of the remaining warnings are meant to be raised at import time for modules that have some issues, so I go ahead and close this now.

maybe we need to reconsider the alfaalfa, sha, ogle warnings about the refactoring, it is not very useful for the user

And I would say we should remove the warnings for these along #2110 and #2555