*Added:*
- File modes `'r'`, `'r+'`, `'w'`, `'x'`, and `'a'` ([\238](https://github.com/glotzerlab/gsd/pull/238)).
*Changed:*
- Test on gcc9, clang10, and newer ([\235](https://github.com/glotzerlab/gsd/pull/235)).
- Test and provide binary wheels on Python 3.8 and newer ([\235](https://github.com/glotzerlab/gsd/pull/235)).
*Deprecated:*
- File modes `'wb'`, `'wb+'`, `'rb'`, `'rb+'`, `'ab'`, `'xb'`, and `'xb+'` ([\238](https://github.com/glotzerlab/gsd/pull/238)).
- \[C API\] `GSD_APPEND` file open mode ([\238](https://github.com/glotzerlab/gsd/pull/238)).