update generate_data.rb with a few tweaks
update generate_data.rb with a few tweaks

Closes LS-3297

Test Plan:

- Test out the --blueprint option to make sure both the bluprint course
  and the associated course ids are printed
- Test that the default account_id of 2 is works without having to
  specify it.
- Try --all_data to see that the outputted data (including new student
  info) is printed

Change-Id: Ie1a6b866bfecdb46dbd7640f5d178678cfea2ecb
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/297112
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Luis Oliveira <4ec7209c0a6350a2c3877fe0e8e120f972fc692a@instructure.com>
QA-Review: Luis Oliveira <4ec7209c0a6350a2c3877fe0e8e120f972fc692a@instructure.com>
Product-Review: Robin Kuss <0b206b54367b2de0334896ea45826f0e3194bd35@instructure.com>

sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms