CircuitOp uses QuantumCircuit.compose, not .combine (Qiskit/qiskit-aqua#1048)
CircuitOp uses QuantumCircuit.compose, not .combine (Qiskit/qiskit-aqua#1048)

* use compose instead of combine

* add test

* add reno
QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py