Esig

- Fixed the range of configurations available.
- Fixed MANIFEST.in, now reflects the updated project structure.

- Fixed problem caused by reading data in from F-contiugous array
- Fixed issue with readme on PyPI.

- Added support for Python3.10.
- Updated build system to use cibuildwheel in Github actions.
- Updated libalgebra to benefit from improvements to performance
- Deprecated tosig submodule. The functions formerly from this module are available
via the top-level esig module. The tosig module will be removed in version 1.0.
- Removed builds on 32-bit Linux for Python 3.8+. There is no Numpy wheels on this
architecture for these versions of Python.

- Switched Linux support to manylinux2010
- Support for 32-bit platforms

- Added builds for Python3.9
- Updated README

- Minor fixes to build routine