This is the first release of geneagrapher-core. Much of the functionality of this package comes from [Geneagrapher](https://github.com/davidalber/geneagrapher), which until now was responsible for retrieving mathematician records directly from the Math Genealogy Project. This package now owns that responsibility. The main features of this release are:
- Functions to support the retrieval of single records or to build entire graphs.
- Arguments to provide callback functions that will receive information during a graph-building process.
- Online documentation to make it easier for others to use this package for retrieving records or building graphs.
- Support for general caching schemes.
Additionally, this release modernizes the coding standards and tools used. Much of the Geneagrapher code this replaces was written in 2008. More recent updates were made in 2011 and 2018, but much has changed with Python and development tools during that time. This release adds type hints, updated and more modern testing, linting, and a continuous integration process. Of course, this release also targets Python 3, instead of Python 2.