Tests are broken

[rheitjoh]

Due to changes in math which were not accompanied with a version change, some tests in Clarc are broken.
Specifically, the changes to representations which were introduced with math commit 3584fba84dd224323e95792f156cde6b45cb0ec1 changed the way, for example, the ZnAdditiveGroup was serialized from an ObjectRepresentation to a RepresentableRepresentation.
These issues are fixed by using the upb.crypto.math version from commit 0430de8a079af16c1ea9f5d9772b222dbffe57ce .

Furthermore, the de.upb.crypto.clarc.acs.protocols.impl.clarc.provecred.Witness class did not have a StandaloneParameter defined for the GenericStandaloneTest which meant it was initialized with a instance set to null, causing that test to fail.
I fixed this by excluding the Witness class from that test for now. It does not have a public constructor anyway, so it would be difficult to add it in any case.

[rheitjoh]

Even if the tests are fixed, there is still the question of how to do the release later. Probably easiest to create math version 0.9 or something and then use that for Clarc once we can release on Maven Central.

[JanBobolz]

I like that idea.