add missing Gray{T} constructor for colorant

[johnnychen94]

fixes #277

[codecov[bot]]

Codecov Report

Merging #278 (033baf4) into master (b8ed378) will increase coverage by 0.02%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #278      +/-   ##
==========================================
+ Coverage   84.04%   84.06%   +0.02%     
==========================================
  Files           8        8              
  Lines         777      778       +1     
==========================================
+ Hits          653      654       +1     
  Misses        124      124              

Impacted Files	Coverage Δ
src/types.jl	97.34% <100.00%> (+0.01%)	:arrow_up:

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[kimikage]

@johnnychen94 I apologize for leaving the development unattended. Thanks for your maintenance, it is much appreciated.

By the way, why is the constructor of Gray{T}(c) needed? It is the job of Colors.jl to convert RGB to Gray. And I wanted to enhance support for AbstractGray other than Gray a couple of years ago.

[johnnychen94]

It is the job of Colors.jl to convert RGB to Gray.

I wasn't that clear on this idea until you mentioned this. The intention was to fix some compatibility issues during the transition from 0.11.0 to 0.11.1 (which should be backward compatible).

During the time @kimikage you were unavailable, nobody realized that the current master contains some unexpected breaking changes, and we (actually, Tim) just released them as patch releases, which was incorrect. This PR is a fixup to that. Also, this is why we have a release-0.11 branch to backport compatible bugfixes and patches.

So, if you decide to move the conversions to Colors, you can safely revert this patch commit in the master branch and continue the development of 0.12 until you're ready.