Rename bash8 to bashate (part 1)

The package has been renamed. We need to add the new
package name to requirements, update all users, and then
remove bash8.

For bashate use version >= 0.2 as required by devstack-gate.

Licence of bashate is Apache 2.0, add it as well.

devstack-gate commit:
https://review.openstack.org/#/c/101267/

Change-Id: I43c65e68780c3f302485a1540e53afd14fd0d72a
Merge "Rename bash8 to bashate (part 1)"