Ported over changes to Sphinx from astropy core package
Revert "Some tweaks to get the sphinx exts (nominally) working on Python 3--haven't tested building actual docs with them yet."

This reverts commit 6e141838a4bc0d784bd796da0e479964e753e4f9.
Remove package-template submodule for now, since it points to @embray’s fork, which causes issues when other projects are trying to clone astropy-helpers.
Clone package-template on-the-fly when testing
Added TODO note
Merge pull request #9 from astrofrog/package-template-submodule

Remove package-template submodule
Skip Sphinx tests on Python 3
Merge pull request #8 from astrofrog/revert-sphinx-changes

Revert sphinx changes
Merge pull request #6 from astrofrog/updated-sphinx

Ported over changes to Sphinx from astropy core package
Ported over fixed references from Astropy core
Make sure that astropy_helpers/src gets installed
Fixed bug that caused re-building of packages
Merge pull request #10 from astrofrog/fix-compiler-c

Make sure that astropy_helpers/src gets installed
Merge pull request #11 from astrofrog/fix-rebuild

Fix rebuilding bug
Copy the _compiler.c file to the package
Merge pull request #14 from astrofrog/fix-compile-c

Copy the _compiler.c file to the package
Changes to setup_helpers.py from astropy/astropy#2223
Changes to test_helpers.py from astropy/astropy#2353, astropy/astropy#2214, and astropy/astropy#2094
Changes to test_helpers.py from astropy/astropy#2198
Merge pull request #21 from astrofrog/update-from-astropy

Update from astropy