API : remove time_as_datetime from Event
API : remove time_as_datetime from Event

closes #78

ericdill/databroker,NSLS-II/metadatastore,ericdill/databroker,tacaswell/metadataStore,tacaswell/metadataStore,hhslepicka/metadatastore,hhslepicka/metadatastore,NSLS-II/metadatastore,arkilic/metadatastore,arkilic/metadatastore