Uproot

In this version:

* tests of TTrees made with ROOT versions from 2009 to the present (and subsequent bug-fixes)
* fully test the `small-evnt-tree-fullsplit.root` and `small-flat-tree.root` files
* can pass empty array instead of `dtype` to avoid allocation
* performance tests, including parallel basket read (main page)
* iterator interface to PyPI

This is a major release, pushed to PyPI.

New iterator interface to read data continuously using a fixed working space memory.

This is a usable version of the package. It has:

* branch reading into arrays with all three types of compression (zlib, lzma, lz4);
* full control over dtype conversion during the copy from the file into arrays;
* variable-length string reading (`TLeafC`);
* memory-mapped files, regular file reading, and XRootD;
* conveniences for querying directory objects, subdirectories, branch names, branch-to-counter associations, etc;
* parallel basket reading and decompression, which accelerates lzma;

Fixed a memory leak in `iterate`: 187.

Fixed a silent error that skipped unrecognized local file names (because, as trivial glob patterns, they don't match); only skipping unmatching names if they actually contain glob characters (`*`, `?`, `[`, `]`, `{`, `}`): 184.

Fixed a bug in TStreamerLoop code generation: 186.

Allow allocators in `std::vector` typenames: 185.

Pass through HTTP(S) query parameters if they exist: 183.

Fixed `uproot4.lazy` error message for the case of no matching files.

Fixed reading of empty files.

Brought up to date with awkward1 0.4.2 (which dropped `cache` parameter from `ak.Array` constructor).

Updated README to indicate that this is the supported version, and point to documentation.

* Implemented TProfile2D's values (111).
* Fixed a bug when reading into Pandas (112).
* henryiii cleaned up CI (113).
* Fixed `arrays`/`iterate`/`concatenate` expressions (116).
* Recognizing full paths of branch names in `arrays`/`iterate`/`concatenate` expressions (117).
* Fix name fetch again (118).
* Variety of fixes for ATLAS xAOD (124).
* andrzejnovak sorted suggested keys in KeyInFileError (127).
* Added tests for Python 3.9 (132).
* TrivialExecutor needs to return a TrivialFuture (accidentally pushed to master).