In a microversion 1.7 change PUT /resource_classes/{name} so that
creation and existence validation of a custom resource class can
happen in a single request and prevent the previous behavior of
being able to update a single resource class to a new name, which is
not desirable.
The previous update_resource_class is still in place to support
microversion 1.2-1.6.
The original resource-classs.yaml sets the default microversion
header to 'latest' so for those existing tests that are using the
old style of PUT, a '1.6' header has been added. New files for
version 1.6 (to add a "no 1.7 behavior here" test) and 1.7 (testing
the new PUT behavior and explicitly verifying POST to create is
still around) are added.
Change-Id: I95f62ab2cb1ab76d18fb52b93f87ed28e4e7b5f3
Implements: bp placement-put-resource-class