v0.5.0

• Requires rasuvaeff/openapi-contract ^0.3 (was ^0.2.1, no longer
  supported). ContractSuite::checkValid() and the reproducer now see the
  contract's response header value validation (response.header.schema,
  response.header.serialization, response.header.unsupported) — a
  server answering X-RateLimit-Remaining: banana for a type: integer
  header is reported instead of passing. Documents whose
  components.securitySchemes lack a supported type or a field the type
  requires no longer compile (InvalidContract). Generated responses keep
  validating: every materialized response header survives the contract's
  simple-style decoding.