LONDON (Reuters) -The Conservative Party will look to whittle down the number of candidates in the contest to replace British Prime Minister Boris Johnson to two by July 20, a member of the committee overseeing the race said, as a fifth candidate joined the field. The Conservative Party’s so-called 1922 Committee will set out the exact rules and timetable for the contest next week after Johnson was forced to quit by his own party. Many lawmakers are pushing for a fast-tracked process. On Saturday, Transport Secretary Grant Shapps became the fifth Conservative lawmaker to officially declare he …