Saving qsymm models

Closes #34

See merge request !23

fix python 3.9 support

See merge request !21

fix multiple warnings

See merge request !19

Anton Akhmerov authored 4 years ago and Dániel Varjas committed 4 years ago

- Use the undeprecaded sympy objects and imports
- Avoid potentially creating an array of arrays with different shape
- Properly use pytest.warns

Mitigate setuptools warning

See merge request !18

Since setuptools-49.2.0 importing distutils before setuptools started to
raise a warning. Moving importing _version.py to the top mitigates this
warning.

This is a decent integration test.
Closes #9.

Coverage percentage is directly reported by GitLab when it parses
the terminal output of the test run. We do not really need a more
detailed coverage report, and if we do so we can generate it locally.

Sparse matrix reshaping is not guaranteed to keep the same sparse
format.

downgrade scipy version requirement

See merge request !12

We use sparse matrix reshaping, which is only in newer version of
scipy. We want to maintain version compatibility with Kwant, so
we get around this by vendoring the relevant functionality and
monkey-patching scipy.