v2.6.4

Full Changelog

Closed issues:

• cmake error while installing libsbp - include could not find load file #705

Merged pull requests:

• SSR STEC and gridded correction message refinements #704
• Change ssr_update_interval to u8. #703
• Purge llvmlite and numba dependencies from generated Python code [ESD-1396] #702
• Don't use hardcoded include/link paths #701