Username: unit_test_repos Password: 
grant select on dba_roles to "UNIT_TEST_REPOS";
grant select on dba_role_privs to "UNIT_TEST_REPOS";
create role UT_REPO_ADMINISTRATOR;
create role UT_REPO_USER;
grant create public synonym,drop public synonym to UT_REPO_ADMINISTRATOR;
grant select on dba_role_privs to UT_REPO_USER;
grant select on dba_role_privs to UT_REPO_ADMINISTRATOR;
grant select on dba_roles to UT_REPO_ADMINISTRATOR;
grant select on dba_roles to UT_REPO_USER;
grant select on dba_tab_privs to UT_REPO_ADMINISTRATOR;
grant select on dba_tab_privs to UT_REPO_USER;
grant execute on dbms_lock to UT_REPO_ADMINISTRATOR;
grant execute on dbms_lock to UT_REPO_USER;
grant UT_REPO_USER to UT_REPO_ADMINISTRATOR with admin option;
grant UT_REPO_ADMINISTRATOR to "UNIT_TEST_REPOS" with admin option;
Object
The unit test repository is a set of tables, views, indexes, and other schema objects that SQL Developer maintains to manage the use of the unit testing feature. (Most of these objects have UT_ in their names.)
Create
  1. Go to View Unit Test
  2. Go to Tool Unit Test > Select Current Repository (If the option is greyed out, go to step 1)
Terminology
Lookup
A lookup is an object that contains, for one or more data types, data values that can be tested. Lookups are mainly used for the following purposes: Sql Developer Unit Test Lookup
Documentation / Reference