Update XrefTest.java
Update XrefTest.java

updated JUnit4 to JUnit5
egonw/BridgeDb,bridgedb/BridgeDb,bridgedb/BridgeDb,egonw/BridgeDb,bridgedb/BridgeDb,egonw/BridgeDb,egonw/BridgeDb,bridgedb/BridgeDb,egonw/BridgeDb,bridgedb/BridgeDb