Consumer: Add Trailing Slash in the replication folder configuration

[tgrall]

1. Consumer get the target folder from a configuration property (rename id cluster.target_folder) t0 make it easier to understand
2. This property is a path that should be ended by a / - add this to the code

[tdunning]

Almost always, when somebody says that a path should always end with a slash, it means that we should be using File(dir, path) to join things rather than string append.