- Change package requirements to python >= 3.9 and specifically exclude pp38 from wheel building
- Retain miniSEED "sequence number" if packing a parsed v2 record
- Change example codes in README.md for usability
- Set defaults for class MS3Record matching msr3_init(). Fixes #3
- Create comprehensive repr() for MS3Record and leave str() as a terse summary. Fixes #4
- Update libmseed to v3.1.3