message: Handle error on event hub start promise
diff: import { EventData, EventProcessorHost, PartitionContext } from "@azure/event-processor-host";
  import { BoxcarType, IBoxcarMessage, IConsumer, IKafkaMessage, IPartition } from "@prague/services-core";
  import { EventEmitter } from "events";
  +import { debug } from "./debug";
  const emit = true;
  @@ -31,9 +32,15 @@ export class EventHubConsumer implements IConsumer {
  eventHubPath: topic,
  });
  - this.eventHost.start(
  + const startP = this.eventHost.start(
  (context, data) => this.handleMessage(context, data),
  (error) => this.error(error));
  +
  + startP.catch((error) => {
  + debug("Error starting event hub");
  + debug(JSON.stringify(error));
  + this.error(error);
  + });
  }
  public async commitOffset(data: any[]): Promise<void> {
  