Pynguin v0.13.0

• Add an assertion-generation strategy based on mutation (thanks to @f-str).

  The new strategy is enabled by default (can be configured using the
  --assertion-generation parameter). It uses a custom
  fork of the mutation-testing framework
  MutPy, which mutates the subject under test and for
  each mutant traces the values of fields and returned by method calls. If these values
  differ between mutant and original code, an assertion is generated based on the result
  on the original subject under test. One can also control whether the strategy shall
  also generate assertions for unchanged values by the --generate-all-assertions flag.

  The release also updates the documentation accordingly.

  Note: This feature is an early prototype of such an assertion generation, which
  might cause unexpected behaviour. You can switch back to the previous strategy for
  assertion generation by setting --assertion-generation SIMPLE.