v0.3.0

• feat(query): support cursors for pagination (startAt, startAfter, endAt, and endBefore) - #45, #46 - @franvera
• feat(dataReducer): handle LISTENER_ERROR case (set path to null if it doesn't exist)
• feat(dataReducer): DELETE_SUCCESS case added which sets item at path to null (i.e. loaded and empty) - #45, RRF 410
• feat(dataReducer): preserveOnDelete config option added to preserve data when DELETE_SUCCESS action is dispatched (NOTE: Will not preserve data removed from state.ordered by LISTENER_RESPONSE action, which is common when having a listener on a list of items)
• feat(statusReducer): requested, requesting and timestamps states now update - @compojoom
• feat(listeners): improve tracking of listeners - RRF 392 - help from @compojoom
• feat(listeners): allowMultipleListeners config option for enabling/disabling whether multiple listeners are attached for the same query
• feat(utils): addWhereToRef and addOrderByToRef utils simplified to be recursive
• feat(dataReducer): CLEAR_DATA action case now accepts boolean and function types for the preserve parameter
• feat(orderedReducer): now accepts boolean and function types for the preserve parameter
• feat(config): config argument of reduxFirestore store enhancer is spread onto internal config (allowing config options passed in either reactReduxFirebase or reduxFirestore)
• feat(config): onAttemptCollectionDelete config option added to allow for running a promise when attempting to run delete on a collection
• feat(tests): tons of tests improvements and additions (full coverage)