Remove wru dependency

[rachel-carroll]

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• fixes remove wru dependency #151

In 2-3 sentences or a brief list, describe changes implemented in this PR

Removes the dependency on the package wru

[rachel-carroll]

details of changes:

1. deleted the following functions:

   • wru_predict_race_wrapper
   • performance_analysis
   • surname_match
   • predict_race_multi_barreled

2. Adjusted surname_summary:

• no longer prints "number of matches by default" or "number of matches after stripping special characters" still prints "number of voters", "number of voters with no last name", "number of voters with special characters"