Stub tests for exps
Implement limit and order for exps, copied from users (missing errors)
Test regular test_root_get_public_operators
Do test_root_get_public_operators_unexisting_ignored
Do test_root_get_public_order
Do test_root_get_public_limit
Do test_root_get_public_malformed_query_valid_field and implement errors
Do test_root_get_public_limit_non_number
Finish testing /exps for url queries