Transitioned to where-function syntax, but it can only supported in Julia 0.7.
Dropped Julia 0.6 support. The last release-versions supporting it are v0.6.x.
Dropped Julia 0.5 support, last release supporting it is v0.5.1
Ditched Julia 0.4 support
Now new invocation: @traitimpl IsBits{X} <- isbits(X)
Implemented Traitor.jl-like syntax.
Now using MacroTools.jl, makes to code look nicer.