Added check in remove_lyra_artifacts to ensure fluxes is a list of
numpy arrays.
remove_lyra_artifacts(): Fixed bug in check of fluxes input type.  If
statement had an OR instead of an AND.  This is now fixed.

find_lyra_events(): Added extension to flare start and end time
definitions.  Namely the times are searched for as before, then
last time that exhibits a continuous increase (for start time) or
decrease (for end time) are said to be the correct times.