Removed duplicate key "cool" from colorScale.

[tkjeldsen]

The key "cool" appeared twice in the colorScale object. The google closure compiler throws an error

stdin:108876: ERROR - Object literal contains illegal duplicate key "cool", disallowed in strict mode
	"cool": [{"index":0,"rgb":[125,0,179]},{"index":0.13,"rgb":[116,0,218]},{"index":0.25,"rgb":[98,74,237]},{"index":0.38,"rgb":[68,146,231]},{"index":0.5,"rgb":[0,204,197]},{"index":0.63,"rgb":[0,247,146]},{"index":0.75,"rgb":[0,255,88]},{"index":0.88,"rgb":[40,255,8]},{"index":1,"rgb":[147,255,0]}],

Maybe colormaps.png also needs to be updated.