A woman got the go-ahead to pursue allegations that GEICO cheated its customers by giving them too small a discount on their auto insurance premiums during the coronavirus pandemic.In a written opinion last week, U.S. District Judge Sharon Johnson Coleman did not rule on the merits of Briana Siegal’s contention that GEICO violated the Illinois Consumer Fraud and Deceptive Business Practices Act with its description of its “GEICO Giveback” program.But Johnson held Siegal had adequately pleaded that GEICO engaged in both …