Your are using the annotation @DatabaseSetUp
from spring-test DBUnit for the database initialization. You should use the annotation @DatabaseTearDown
too.
From the spring-test DBUnit documentation :
The @DatabaseTearDown annotation can be used to reset database tables once a test has completed. As with @DatabaseSetup the annotation can be applied at the method or class level. When using @DatabaseTearDown use the value and type attributes in the same way as @DatabaseSetup.