Re-introduce Christian Neumüller to AUTHORS
Re-introduce Christian Neumüller to AUTHORS

The introduction was reverted by cd29d56

Akasurde/pytest,nicoddemus/pytest,alfredodeza/pytest,tomviner/pytest,RonnyPfannschmidt/pytest,The-Compiler/pytest,pytest-dev/pytest,tomviner/pytest,The-Compiler/pytest,nicoddemus/pytest,markshao/pytest