Merge remote-tracking branch 'upstream/staging' into map
Make pyfits an optional dependancy with astropy.io.fits first
Build deps and setup.py changed from pyfits to astropy
Merge remote-tracking branch 'upstream/staging' into pyfits

Conflicts:
	.travis.yml
	setup.py
merge from upstream (map refactor)
fix to map grid plotting which got lost in refactor
fixed bug in plotting of compositemaps
Merge pull request #489 from ehsteve/map

A few bug fix for refactor and plotting
Fix fails due to pyfits.core
Merge pull request #488 from Cadair/pyfits

Deprecate pyfits in place of astropy
Merge branch 'staging' into glymur
Merge map refactor and fix a couple of bugs