Remove legacy core project

[jeffmay]

We have moved all of our code off of the old algebra. We should remove it to avoid confusion and improve code coverage. Also, this enables some refactoring that I hope to complete before releasing v1.0.0

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (v1@6de9060). Click here to learn what that means.
The diff coverage is n/a.

❗ Current head f51cafd differs from pull request most recent head 5d0ac99. Consider uploading reports for the commit 5d0ac99 to get more accurate results

@@          Coverage Diff          @@
##             v1      #97   +/-   ##
=====================================
  Coverage      ?   60.38%           
=====================================
  Files         ?       93           
  Lines         ?     1949           
  Branches      ?       18           
=====================================
  Hits          ?     1177           
  Misses        ?      772           
  Partials      ?        0           

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