Create and run transparency score vs. city population regression model

[castroluis2768]

• Run an OLS regression of transparency score on population
• Extract the residuals (i.e the difference between the predicted transparency score and the actual transparency score)
• Rank the cities by the absolute value of the size of the residuals
• Generate CSV dataset with the following variables: ST_FIPS, city_name, state, predicted_transparency_score, transparency_score, residual, rank