Removed some reqs. Force protobuf ver

seriate-> ortools -> protobuf fails for protobuf ver 4 or higher, so this is no enforced in the reqs.

schur stability

Minor change to make schur more stable in rare cases.

riskparityportfolio

v0.6.0

reqs

more stuff

v0.5.21

Merge branch 'main' of https://github.com/microprediction/precise

more weak ports

v0.5.16

ver

fixed signatures

A few misc skaters had incorrect signatures

imp

v0.5.12

Merge branch 'main' of https://github.com/microprediction/precise

comparisons

v0.5.11

ver

more cov skaters

Added more cov skaters that use weakening

ledoit wolf name cleanup etc

v0.5.9

ver