Make SinkBinding v1beta1 the stored version and add a migration tool

[nachocano]

Problem
In 0.17, we promoted SinkBinding to v1beta1.
This is to track that we should make v1beta1 the storage version for 0.18, and we should add a migration tool for it.
Similar to: https://github.com/knative/eventing/blob/master/config/pre-install/v0.16.0/storage-version-migration.yaml

Persona:
Which persona is this feature for?
Developer

Exit Criteria
SinkBinding in v1beta1 and able to migrate

Additional context (optional)
#3613

[nachocano]

/assign @nlopezgi

[nlopezgi]

i think this can be closed now that #3895 is in

[nlopezgi]

/close

[knative-prow-robot]

@nlopezgi: Closing this issue.

In response to this:

/close

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[nlopezgi]

/reopen
per #3895 (comment): we also need to update the CRDs to mark that we are storing v1beta1 now, so that a fresh install has that, not just the updated clusters.

[knative-prow-robot]

@nlopezgi: Reopened this issue.

In response to this:

/reopen
per #3895 (comment): we also need to update the CRDs to mark that we are storing v1beta1 now, so that a fresh install has that, not just the updated clusters.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[nachocano]

/close
Fixed by #3942
I think it didn't automatically close because the Fixes # needs to be in different lines...
Thanks @nlopezgi !!!