Allowing procs to be used to allow series options.
Merge pull request #151 from bradly/procs_for_series

Allowing procs to be used to allow series options. thanks to @bradly!
revert to 1.5.0
HighChart#to_ary returns a Hash

This is fixed by doing the default action when the method name is
'to_ary'.
Merge pull request #153 from ThijsWouters/master

HighChart#to_ary returns a Hash