Show traceback for migration error

[abulte]

$ udata db info udata:2020-07-15-dummy
➢ udata:2020-07-15-dummy ............................................... [2020-07-15 15:08]

Migrate ................................................. [2020-07-15 15:01]
  │
  │ yup
  │
  │ Traceback (most recent call last):
  │   File "/Users/alexandre/Developer/Etalab/udata/udata/migrations/__init__.py", line 219, in execute
  │     self.module.migrate(db)
  │   File "<string>", line 8, in migrate
  │ Exception: nope nope nope
  │
  │
  └──[KO]

Migrate ................................................. [2020-07-15 15:08]
  │
  │ yup
  │
  │
  └──[OK]

$ udata db migrate
➢ udata:2020-07-15-dummy ............................................... [Apply]
  │
  │
  │ Traceback (most recent call last):
  │   File "/Users/alexandre/Developer/Etalab/udata/udata/migrations/__init__.py", line 220, in execute
  │     self.module.migrate(db)
  │   File "<string>", line 2, in migrate
  │   Exception: yup yup
  │
  │
  └──[KO]