By default HSQL creates a schema called PUBLIC. source: HSQL documentation
Seeing as the schema name is never seen in the tests (named queries/entity manager to do the interactions) you can change the hibernate properties to use this PUBLIC schema
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" />
<property name="hibernate.default_schema" value="PUBLIC"/>
<property name="hibernate.hbm2ddl.auto" value="create-drop" />
</properties>
OR
just leave out the default_schema from the properties list and it uses PUBLIC anyway
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" />
<property name="hibernate.hbm2ddl.auto" value="create-drop" />
</properties>