Added back create_an_observation.story & modified retire_unretire_concept_drug.story

Moved create_an_observation.story from oldstories folder to
stories/administration/observation. Changed When step in for
retire_unretire_concept_drug.story to take the name of the concept drug
it is supposed to retire and unretire (the concept drug must already
exist in the db)
Code cleanup

delete files from oldstories folder since have moved them elsewhere in
the test suite