Would it be difficult to add support for using symbols as keys to ZArray?

[alex-s-gardner]

Working with DataFrames, I've become accustomed to using symbols for keys and I'm wondering if it's trivial to add support for this in Zarr?

e.g.
z = zopen(path2zarr);
z[:var_name]

[meggart]

Would not be difficult at all. Here is the getindex implementation for a ZGroup

Zarr.jl/src/ZGroup.jl

Lines 69 to 77 in cbcaead

	function Base.getindex(g::ZGroup, k)
	if haskey(g.groups, k)
	return g.groups[k]
	elseif haskey(g.arrays, k)
	return g.arrays[k]
	else
	throw(KeyError("Zarr Dataset does not contain $k"))
	end
	end

, we could either add a method for k::Symbol or justv convert the keys to Strings in general.

[meggart]

A PR would be great.

[alex-s-gardner]

#130