Only remove first forward slash if it's the leading character.  This is in case the csv
group column contains leading slashes.  Previously, it removed the slash in between
the first and second group if there was no leading one resulting in this match never
succeeding.  eg, it would turn parent/child_1/child_2 into parentchild_1/child_2.
Merge pull request #7 from logicmonitor/bmetcalf-group-bug

Only remove first forward slash if it's the leading character.  This is ...