TraditionalRLSetting has wrong number of tasks

[lebrice]

setting = TraditionalRLSetting(dataset="MountainCarContinuous-v0", nb_tasks=1)

Will actually alternate between two tasks rather than one during testing. (Need to double-check that this isn't happening during training as well).

This is caused by the task schedule having two keys: one at step 0 (initial conditions) and one that is supposed to only be used in the ContinualRLSetting as the "final conditions", but in this case it is interpreted as the boundary to a second task.