v1.16

• Ignored files: .ipynb_checkpoints, .benchmarks
• Reduce configuration (elide defaults) and remove copy-pasta stuff
  from docs.
• Various CI, packaging, metadata and badge fixes.
• Added .readthedocs.yml config file.
• Added support for Python 3.8, dropped Python 3.4.
• Added pyproject.toml to solve a bunch of packaging problems when
  setuptools-scm or Cython/CFFI are enabled.
• Added options to customize where docs, repository and packages are
  hosted.
• Added options to customize where tests are located.
• Added GNU LGPL licenses.