global: initial REST validation API

[mvesper]

• Adds _dryrun key to the webhooks payload to validate the action.

Signed-off-by: Martin Vesper martin.vesper@cern.ch

[jirikuncar]

What about adding dry-run or only-validate option to the endpoints?

Alternatively, I would change the name from Test* to Validate* and use inheritance instead of specifying the validator twice.

class ValidatorFoo(ValidatorBase, Foo):
    pass

[jirikuncar]

LGTM

[mvesper]

@jirikuncar I saw that you 'thumbed-up' the commit message. I changed it though. Is it still valid? Should be fine otherwise :)