refactored presto init-action to conform with shell-style guidelines (#232)
refactored presto init-action to conform with shell-style guidelines (#232)


lukeFalsina/dataproc-initialization-actions,lukeFalsina/dataproc-initialization-actions,dennishuo/dataproc-initialization-actions,dennishuo/dataproc-initialization-actions,GoogleCloudDataproc/initialization-actions,GoogleCloudDataproc/initialization-actions,GoogleCloudDataproc/initialization-actions