SkyPy 0.4

Changes

• move work-in-progress modules to module branches (#389)
• rename skypy.galaxy to skypy.galaxies (#413)
• move galaxy.size and galaxy.ellipticity to galaxy.morphology (#410)
• refactored kcorrect spectrum functions (#379, #386, #391)
• obtain metallicity and star formation rates from templates (#397, #400)
• new utils.photometry module (#411)
• use speclite package for magnitude computations (#292, #368)
• improved examples (#385, #388, #395)
• refactored Schechter stellar mass sampling (#394)
• random projection of triaxial ellipsoid (#407)
• change fsky to sky_area (#314)
• simple construction of quantities in config files (#316)
• drop support for astropy 3 (#353)