Version 2.8.0

What's Changed

• Fix speciation moves for parallel tempering by @mlund in #419
• Custom group to group pair-potential by @mlund in #421
• Rename namespace and base classes by @mlund in #422
• Upgrade nanobench from v3 to v4 by @mlund in #423
• Table cleanup by @mlund in #420
• Fix GCC warnings

Full Changelog: v2.7.0...v2.8.0