travis: re-enable geth tests with genesis caching
travis: re-enable geth tests with genesis caching

hackaugusto/raiden,tomaaron/raiden,tomaaron/raiden,tomaaron/raiden,tomashaber/raiden,hackaugusto/raiden,tomashaber/raiden,charles-cooper/raiden,tomaaron/raiden,charles-cooper/raiden,tomashaber/raiden,tomashaber/raiden,tomashaber/raiden