[Hawkular-dev] Travis cache pruning

Hi *, because we had no cache pruning in place, the cached ~/.m2/repository in hk main became too bing. As a consequence of that, when Travis attempted to zip the cached folder, the cache archive made the disk full and not only that the cache could not be uploaded outside of the transient docker container, also all subsequent tasks (deployment of SNAPSHOTs) failed. I could not find a working pruning script quickly enough. To solve the problem temporarily at least, I deleted the cache manually under https://travis-ci.org/hawkular/hawkular/caches Best, Peter