typo in correlated noise routines
Merge pull request #514 from GalSim-developers/#511

#511 Start moving GSObjects (and others) toward a more immutable design
Have astropy import check for scipy.optimize specifically.  #525
Update some CHANGELOG items.
Merge branch 'master' into #526

Conflicts:
	galsim/correlatednoise.py
Add unit tests that fail for noise.getRNG() when noise was constructed without an explcit BaseDeviate object
(#526)