Update RB notebooks

[ShellyGarion]

Summary

Updating RB tutorials following API changes in ignis.

Details and comments

qiskit-community/qiskit-ignis#334

[nkanazawa1989]

LGTM. just one small comment

the description above cell 14 should be updated because it doesn't take qobj.

The function gates_per_clifford takes a compiled qobj and outputs the number of basis gates in each circuit.

[nonhermitian]

Note that all the tutorials now go in the Qiskit documentation: https://github.com/Qiskit/qiskit

[ShellyGarion]

Note that all the tutorials now go in the Qiskit documentation: https://github.com/Qiskit/qiskit

Thanks, so I'll close this PR when I will open a new one in the right place.

[ShellyGarion]

@nkanazawa1989 - could you please review the updated notebook?
when it's done, then I'll close this PR and move the notebook to qiskit docs.

[nkanazawa1989]

looks good. one minor suggestion: cell 14 can be simplified

for basis_gate in basis_gates:
    print("Number of %s gates per Clifford: %f "%(basis_gate ,
                                                  np.mean([gates_per_cliff[0][basis_gate],
                                                           gates_per_cliff[2][basis_gate]])))

because gates_per_cliff is dictionary.

and the PR should be on hold until ignis 0.3 is released.

[ShellyGarion]

Opened a new PR in qiskit docs: Qiskit/qiskit#866

[ShellyGarion]

Fix #892.

[ShellyGarion]

Closing since notebook 5a was moved to 4, and 5d was removed.