Added master key creation

Author: uc-msft

samples/features/sql-big-data-cluster/bootstrap-sample-db.sql

@@ -15,6 +15,10 @@ GO
 
 USE sales;
 GO
+-- Create database master key (required for database scoped credentials used in the samples)
+IF NOT EXISTS(SELECT * FROM sys.databases WHERE name = DB_NAME() and is_master_key_encrypted_by_server = 1)
+	CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'sql19bigdatacluster!';
+
 -- Create default data sources for SQL Big Data Cluster
 IF NOT EXISTS(SELECT * FROM sys.external_data_sources WHERE name = 'SqlDataPool')
 	CREATE EXTERNAL DATA SOURCE SqlDataPool