[9.x.x] test extra pulls in plone.tiles

[jensens]

https://github.com/plone/plone.restapi/blob/42387edcb758396fbc97d0ded59de87d63767ea6/setup.py#L42

But plone.tiles is not Plone Core. This should be optional in tests.

[tisto]

@jensens ok, the tiles endpoint is deprecated, so this should go away asap.

[tisto]

@jensens we would have to cut a plone.restapi release 9 to get rid of the plone.tiles dependency:

https://github.com/plone/plone.restapi/blob/2cbdefe6155c6ec80305b5798b719e002156929f/docs/source/tiles.rst#tiles

I am reluctant to do so for such a trivial thing. I guess an alternative could be removing the test dependency and the tests in the 8 branch if that dependency causes troubles.

[jensens]

I also do not think this justifies a new release. The test could have a conditional import and a skipIf, that would be enough.