LONDON (Reuters) - Royal Dutch Shell's female employees in Britain earned on average 18.6 percent less than their male colleagues in 2018, the company said in a report on Wednesday, narrowing the gender pay gap from 2017's 22.2 percent.The difference in earnings between men and women has provoked significant anger among many women in recent years and sparked a public debate in Britain over why pay is still so different for men and women."We are confident that we pay men and women equally for..