add rxjs dependencies for test

[ktong]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Bug fix: test failed when service use map from rxjs

• What is the current behavior? (You can also link to an open issue here)

Failed: undefined is not a constructor

• What is the new behavior (if this is a feature change)?

Test passed

• Other information:

[PatrickJS]

good catch