Examples and Tests for Sqoop Execution

1) Included examples for both Sqoop Export and Import with Execution
2) Added tests for the examples
3) Added tests for the SqoopExecution trait especially for the failure scenarios
There was some confusion with dealing with sql queries. In https://github.com/CommBank/parlour/pull/47 we handle sql queries in following way: 
1. Parlour API accepts now only ParlourDsl, 
2. If sql query is set in ParlourDsl then evaluate it before export/import
3. if 'deleteFromTable' is True (only in export case), then evaluate sql query (if any), delete from table, export. There are two Jobs/Flows for export: export with appending, export with deleting.