Updates to ColorSchemes to work with the new Images.jl 0.6

• drops support for Julia 0.4
• works with and requires Images.jl 0.6
• some changes to function names

v1.2.1

viridis, magma, inferno, plasma added

v1.1.0

reworked:

• color schemes are now symbols and not stored as text in text files
• ColorBrewer schemes translated and included
• get() replaces colorscheme() sampling function

Updates for Julia version 0.5

v0.2.0

update test requirements