use ImageBase.restrict

[johnnychen94]

A breaking change is that vector inputs now also use restrict; this is unavoidable if we want to reduce the dependencies.

julia> @time using ImageInTerminal
# master:  2.054145 seconds (4.89 M allocations: 353.901 MiB, 4.90% gc time, 0.17% compilation time)
# PR: 1.064598 seconds (2.01 M allocations: 144.469 MiB, 0.32% compilation time)

[johnnychen94]

restrict requires ColorVectorSpace to work. I bump the lower bound of ImageCore to 0.9 because it loads ColorVectorSpace JuliaImages/ImageCore.jl#157

[johnnychen94]

Guess @oxinabox might be interested in knowing this since it makes ReferenceTests a lot lighter.

julia> @time using ReferenceTests
# before: 2.225183 seconds (5.65 M allocations: 388.105 MiB)
# after: 1.298767 seconds (2.54 M allocations: 174.356 MiB, 7.41% gc time)