Error when concatenating unstyled unicode symbol

[hexaeder]

julia> using StyledStrings
julia> "τ" * styled"{blue:blue}" # errors
"Error showing value of type Base.AnnotatedString{String}:
ERROR: StringIndexError: invalid index [2], valid nearby indices [1]=>'τ', [3]=>'b'

when explicitly giving default style it works

styled"τ" * styled"{blue:blue}" # no style errors
styled"{default:τ}"*styled"{blue:blue}" # explicit default style works

[tecosaur]

This is really two issues:

1. An oversight with multi-codeunit strings
2. Printing trying to access invalid codeunits

(2) has already been fixed in #86, and (1) seems to be working in a development version of Julia + StyledStrings locally, so I suspect this is just a matter of the fixes being released.

julia> s = "τ" * styled"{blue:blue}"
"τblue"

julia> show(s)
Base.AnnotatedString{String}("τblue", [@NamedTuple{region::UnitRange{Int64}, label::Symbol, value}((3:6, :face, :blue))])

[tecosaur]

I'll check the compat release of StyledStrings for this issue on the weekend.