paletteer 1.7.0

• Updated argument checking to be more precise and uniform. (#174)
• Add missing scico palettes. (#168)
• Added new palettes from ButterflyColors, feathers, ggsci, khroma, PrettyCols, and tayloRswift. (#182)
• 4 palettes have been added from blueycolors package. (#155)
• 5 palettes have been added from amerika package. (#158)
• 5 palettes have been added from amerika package. (#158)
• 15 palettes have been added from Rdune package. (#157)
• 41 palettes have been added from poisonfrogs package. (#183)