Drop DataArrays requirement?

[tlnagy]

@ararslan, @alyst, Any chance that this package will get updated in response to JuliaData/DataFrames.jl#1008?

[ararslan]

I think that's the plan, though Alexey would know better than I would since he seems to be the primary developer/maintainer of this package. It's my understanding that DataArrays will eventually go extinct as the stats ecosystem adopts NullableArrays.

[tlnagy]

Good to know. This is the main thing keeping Gadfly's tests from passing when using DataFrames master AFAIK.

[amellnik]

Related: JuliaData/DataFrames.jl#1092

[rofinn]

This could probably happen now that DataTables has been backported.