AxisArrays exports axes, which conflicts with Base.axes

I noticed that the `axes` function is exported in AxisArrays, but this is a Base function as well. I would like to know whether this was a deliberate choice or this is a bug?

```
julia> using AxisArrays

julia> A = AxisArray(rand(2), a=[1,2]);

julia> axes(A)
WARNING: both AxisArrays and Base export "axes"; uses of it in module Main must be qualified
```