Currently functional tests cannot test the DELETE method on some API
endpoints, e.g.
DELETE /placement/traits/{name}
This is because it is not setting the request headers to have the
right microversion API - this setting was added for GET / PUT / POST
in I681712ac37f732c7803c68f6c7d1eae9f2877d3d, but not for DELETE.
Therefore the microversion defaults to 1.0 which for some endpoints is
lower than the required version, e.g. the endpoint above requires a
minimum microversion of 1.6, which is when this API was introduced.
This results in any invocation of _fake_delete() receiving a 404
error, although this error has not been experienced so far because
nothing uses _fake_delete() yet.
In order to enable future functional tests which hit this API call,
set the request headers in a manner consistent with the other HTTP
methods for the same endpoint.
Change-Id: I2e2d9a9ae12404fe66eae64f8767e348012d7932
94d83e40e1