code: function removeReason (reason, criteria) {
      if (!criteria) criteria = { }
      var log = this
      return this.store.removeReason(reason, criteria, function (action, meta) {
        log.emitter.emit('clean', action, meta)
      })
    }
docs: Remove reason tag from action’s metadata and remove actions without reason
  from log.
  
  @param {string} reason Reason’s name.
  @param {object} [criteria] Actions criteria.
  @param {number} [criteria.minAdded] Remove reason only for actions
  with bigger `added`.
  @param {number} [criteria.maxAdded] Remove reason only for actions
  with lower `added`.
  @param {string} [criteria.olderThan] Remove reasons only for actions
  with bigger `id`.
  @param {string} [criteria.youngerThan] Remove reason only for actions
  with lower `id`.
  @param {string} [criteria.id] Remove reason only for action with `id`.
  
  @return {Promise} Promise when cleaning will be finished.
  
  @example
  onSync(lastSent) {
  log.removeReason('unsynchronized', { maxAdded: lastSent })
  }