Cocotb

This is a maintenance release in the 1.5 release series.

**Bugfixes**
- Prevent pytest assertion rewriting (2028) from capturing stdin, which causes problems with IPython support (1649, 2462)
- Add dependency on cocotb_bus to prevent breaking users that were previously using the bus and testbenching objects. (2477)
- Add back functionality to cocotb.binary.BinaryValue that allows the user to change `binaryRepresentation` after object creation. (2480)

Release notes: https://docs.cocotb.org/en/v1.5.0/release_notes.html#cocotb-1-5-0-2021-03-11
Release announcement: https://www.fossi-foundation.org/2021/03/11/cocotb-1-5-0
PyPI release: https://pypi.org/project/cocotb/1.5.0/

Release notes: https://docs.cocotb.org/en/stable/release_notes.html#cocotb-1-4-0-2020-07-08
Release announcement: https://fossi-foundation.org/2020/07/08/cocotb-1-4-0
PyPI release: https://pypi.org/project/cocotb/1.4.0

Release announcement: https://lists.librecores.org/pipermail/cocotb/2020-June/000079.html
PyPI release: https://pypi.org/project/cocotb/1.4.0rc1/

Iterating over `for generate` statements using VHPI has been fixed. This bug caused some simulators to crash, and was a regression in version 1.3.1. (1882)

Release notes: https://cocotb.readthedocs.io/en/latest/release_notes.html#cocotb-1-3-1
Release announcement: https://lists.librecores.org/pipermail/cocotb/2020-March/000077.html
PyPI release: https://pypi.org/project/cocotb/1.3.1/