Bump sphinx minversion to 1.7

Updating minimum sphinx verison to 1.6

Fix app.info() deprecation warning for Sphinx >= 1.6

Add an extension that allows intersphinx to be disabled on the command-line

Co-Authored-By: astrofrog <[email protected]>

Update matplotlib intersphinx URL

Use intersphinx of released version rather than dev

Include pillow in dependencies

Test with developer version of Sphinx

Make default Sphinx configuration versioned

Added package layout

Removing python2 support

Allow Sphinx doctest extension to recognize standard doctest directives

Use mathjax instead of imgmath

Mark sphinx extensions as parallel-safe

Adding sphinx dev testing to the travis matrix

Fix errors reported by pyflakes

Python intersphinx target has moved to https

Adding astropy hosted intersphinx inventories as backup versions

Move numpydoc and sphinx-automodapi to astropy_helpers.extern

Changing deprecated usage of 2 latex config items

Adding collections.abc classes to the local sphinx inventories

Adding collections.Mapping to the local python3 inventory

Cleanup PR

Adds the suppress_warnings config item, and skips the workaround when it works (sphinx>=1.4.2)

Python version dependent local sphinx inventory file

Fixed one of the warnings raised by sphinx 1.4

Use mathjax for math rendering on readthedocs

Make the font of graphviz diagrams match the HTML

Better HiDPI support.

Add autodoc attrgetter workaround for classes

Remove dependency on six and enable sphinx tests on Python 3

Skip argument of doctest-skip in the sphinx output

make changelog sphinx extension also apply to whatsnew pages