DummyRequest uses wrong registry if it is created before testing.setUp is executed

[mcdonc]

testing.DummyRequest uses the wrong registry (the global registry) as self.registry if a dummy request is created before testing.setUp() is executed (setUp pushes a local registry onto the threadlocal stack). To fix: use a property for request.registry instead of an attribute.

[mcdonc]

• testing.DummyRequest used the wrong registry (the global registry) as
  self.registry if a dummy request was created before testing.setUp
  was executed (testing.setUp pushes a local registry onto the
  threadlocal stack). Fixed by implementing registry as a property for
  DummyRequest instead of eagerly assigning an attribute.
  See also DummyRequest uses wrong registry if it is created before testing.setUp is executed #165

Closed by 8af47bc.