Fixed an issue which caused unit test comparing Map and pyfits data to take a long time.
Fixed an issue which caused unit test comparing Map and pyfits data to take a long time.

Alex-Ian-Hamilton/sunpy,dpshelio/sunpy,Alex-Ian-Hamilton/sunpy,mjm159/sunpy,dpshelio/sunpy,mjm159/sunpy,dpshelio/sunpy,Alex-Ian-Hamilton/sunpy