changes API
minor fix
API change
finish execution when all batches are processed
follow API change
adds validation feature
Supports validation code

- executes `test()` in users' code and see if any exception is raised
- example/01,06 work with validation code
- supports csv & json output for LocalFile and Stdout

Signed-off-by: Sho Nakatani <lay.sakura@gmail.com>