v0.9.0

The main changes are a fix to how uncertainty in the selection function estimate is calculated and adding the spline spin models from Golomb & Talbot.

What's Changed

• Fix selection variance post processing by @ColmTalbot in #64
• Interped Class and Spline Spin Models by @jacobgolomb in #62
• BUGFIX: fix getting names of class instances by @ColmTalbot in #66
• added change to vt.py to use mu rather than marginalized pdet by @jacobgolomb in #63

Full Changelog: v0.8.1...v0.9.0