v0.14.0

• Changed. Accepts rasuvaeff/property-testing-core ^0.10 alongside
  ^0.5–^0.9, and develops against rasuvaeff/property-testing-testo
^0.10 as well. None of the 0.10 contract freeze reaches this package: it
  never called FilesystemCorpus::fromEnv(), reads no CounterExample::$skips,
  names neither GenerationExhausted nor PostconditionViolation in code
  (two comments mention the former by its old name), and types every
  generator as ArbitraryInterface — which is exactly what Gen::* returns
  from 0.10 on. The suite (866 tests) is green against core 0.10.0 and the
  adapter 0.10.0.
• Docs. The requirements line in both READMEs names the constraints
  composer.json actually declares: openapi-contract ^0.11 (it said
  ^0.8 / ^0.9 / ^0.10 since 0.13.0 moved on) and property-testing-core
^0.5–^0.10.