v0.5.0

• Requires rasuvaeff/understudy ^0.8, and requires it as a single term. The
  accumulating union it carried (^0.4 || ^0.5 || …) had to be widened by hand
  on every core release, and a package that misses one becomes uninstallable
  beside its own engine.
• ->returns(...)->times(5, 2) is reported as impossible again. The
  cardinality rule read only the immediate receiver of times(), so it fired
  on expect(...)->times(5, 2) and stayed silent on every spelling with a link
  in between — including the one the engine's own README recommends for a
  repeated call.
• times(maximum: 5, minimum: 1) is no longer reported as impossible. The
  bounds were read positionally, so a named call with the arguments in the
  other order looked like (5, 1). Correct code turned red, with no way around
  it but removing the extension.
• A specification that reaches its double through a helper is silent.
  when(fn () => $this->gate()->find(1)), $double->find($this->id()) and
  $this->passThrough($double->find(1)) were all reported as "the closure
  makes 2 calls". The engine throws on the first call that lands on a double
  and never sees the rest, so a call that is the receiver of another, or one
  made on $this, is not a second specified call. The total still answers "no
  call at all", so a specification that reaches its double only through a
  helper is not accused of specifying nothing either.
• understudy.matcherLeak no longer accuses a matcher that arrives
  indirectly. The rule compares file offsets against the textual range of the
  when() call, so a matcher hoisted into a variable, stored on a property or
  written inside a closure handed over later fell outside every range and was
  called a leak. A matcher inside any closure is now left alone — the closure
  has not run — and a matcher that is assigned rather than passed is nobody's
  argument.
• wire() builds a shape for a ?Contract parameter. Null in the union
  answered no class name, so no shape was built for the key and
  $wired['doubles']['clock'] stayed object — "Call to an undefined method
  object::now()" on working code, against a docblock promising that ?Contract
  is the same double.
• Includes the matcher-location and returned-call fixes merged after 0.4.1
  (#23), which had not been released.