Document jitter options in poppy.Instrument docstring
Move poppy.Instrument attributes up to the class level so Sphinx can find them
Typo in Instrument.filter docstring
Merge branch 'master' into docs_refresh

Conflicts:
	poppy/instrument.py
Remove astropyautosummary Sphinx extension
Update Instrument docstring for jitter
Convert exception into conditional in Instrument._applyJitter
Update pysynphot install instructions in installation.rst
Merge pull request #31 from josePhoenix/docs_refresh

Docs refresh (work-in-progress)