Log Message:
py-bitarray: updated to 2.3.4

2021-09-12   2.3.4:
-------------------
* Fix `util.ba2int()` for frozenbitarrays.  A bug was introduced in 2.3.0
  as `.tobytes()` no longer treats pad bits for read-only buffers as zero.
* add tests

2021-09-05   2.3.3:
-------------------
* improve some error messages
* add tests

2021-08-23   2.3.2:
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* fix slice assignment for shared buffer with offset case
* add tests (including internal debug mode tests for `buffers_overlap()`)

2021-08-20   2.3.1:
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* fix special shared buffer copy case
* add and improve tests