updated spark-submit command to bigtable-spark-submit
updated spark-submit command to bigtable-spark-submit

GoogleCloudPlatform/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,GoogleCloudPlatform/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,GoogleCloudPlatform/cloud-bigtable-examples,GoogleCloudPlatform/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,sduskis/cloud-bigtable-examples