KML.jl generates invalid XML

[dominformant]

When writing a KML Document to a file, the XML header is generated in a wrong order leading to invalid XML files. The header is generated as <?xml encoding="UTF-8" version="1.0"?>, however the specification says, that the order has to be <?xml version="1.0" encoding="UTF-8"?>.
I assume this comes from the "attributes" being defined in a Dict, which is unorderes as far as I understood.

KML.jl/src/KML.jl

Line 142 in 32bb3fe

Node(XML.Declaration, nothing, Dict("version" => "1.0", "encoding" => "UTF-8")),

[joshday]

I recently changed the internals of XML.jl from Dict to OrderedDict. I plan to do the same here.