Issues running some routines

[killillian]

Some errors encountered while trying to run existing routines in contrib.py:

• Routines using OfflineRepositoryRoutine (CommitInfoMiningRoutine and OfflineCommitCountsRoutine) raise an error due to Sandia proxies:

  OfflineRepositoryRoutine Encountered an unexpected exception (<class '_pygit2.GitError'>). failed to connect to github.com: Resource temporarily unavailable

• The routine GambitCommitAuthorshipInferenceAnalysis does not instantiate in manager.py

  ValueError: Failed to instantiate routine matching name GambitCommitAuthorshipInferenceAnalysis

• The routine TeamSizeAndDistributionAnalysis raises the same error as above. After adding the line from reposcanner.contrib import TeamSizeAndDistributionAnalysis to manager.py, it still returns the same error

Additionally, a small inconsistency in the main README.md:

• In its last section, "How to extend functionality," the main README.md mentions an example file called stars.py. However, this file doesn't seem to exist in the main branch of the repository.