Uproot

Updated dependence to awkward 0.8.0 and uproot-methods 0.4.0. Since one can now use `awkward.JaggedArray` or `awkward.numba.JaggedArray`, all of the array-fetching functions now have an `awkwardlib` parameter where you can specify `awkwardlib="awkward.numba"` (as a string or a module object).

When `awkward.cuda` exists, this will be the mechanism for reading data directly from ROOT files onto GPUs with [CuPy](https://cupy.chainer.org).

Remove README from data_files

Fixed some (erroneous) `Interpretation` identifiers. Minimum version required for [uproot-skyhook](https://github.com/diana-hep/uproot-skyhook).

Added `reportpath` and `reportfile` parameters to `uproot.iterate`.

Fixes 205: `tree.iterate` on a TTree that has any zero-basket branches.

Merged 211, a feature allowing ROOT files to be read over authenticated HTTP (requiring the "requests" package) and 214, a bug-fix for matching branches to streamers under a TStreamerObject (see 213 for details).

Fixes 201. Large files have 64-bit seek points, which isn't reflected by the `TBranch.fBasketSeek` streamer; it depends on the preceding byte being `2`, rather than `1`.