v0.0.8

Summary:
Add some more attributes to the Timescale class for astro time conversions.

Itemized Changes:

• feat: added attributes for ut1_utc and gps_utc (#131)
• fix: add ut1_utc1 to ut1 (#132)
• feat: add utc attribute (#132)

Full Changelog: 0.0.7...0.0.8