More descriptive output

What's Changed

• Make sure baseline hazard is serializable and returned as result by @dsmits in #142
• Different kinds of integration tests are now subcommands by @dsmits in #143
• 37 benchmark verticox with multiple features by @dsmits in #144
• 141 demo notebook by @dsmits in #148
• 98 parse results in verticox client by @dsmits in #149

Full Changelog: v0.4.0...v0.5.0