update grover+oracle example in readme
@@ -42,7 +42,7 @@ $ python
```python
>>> from qiskit import Aer
->>> from qiskit.aqua.components.oracles import SAT
+>>> from qiskit.aqua.components.oracles import LogicExpressionOracle
>>> from qiskit.aqua.algorithms import Grover
>>> sat_cnf = """
>>> c Example DIMACS 3-sat
@@ -54,7 +54,7 @@ $ python
>>> -1 2 3 0
>>> """
>>> backend = Aer.get_backend('qasm_simulator')
->>> oracle = SAT(sat_cnf)
+>>> oracle = LogicExpressionOracle(sat_cnf)
>>> algorithm = Grover(oracle)
>>> result = algorithm.run(backend)
>>> print(result["result"])
