adjust test of convert_iupac_to_smiles_and_inchi web service

the format of the returned json has slightly changed, see below, therefore
we are now testing the values returned in the json

before:

```json
{
  'inchi': 'InChI=1/C7H5N3O6/c1-4-6(9(13)14)2-5(8(11)12)3-7(4)10(15)16/h2-3H,1H3',
  'smiles': '[N+](=O)([O-])C1=C(C)C(=CC(=C1)[N+](=O)[O-])[N+](=O)[O-]',
  'stdinchi': 'InChI=1S/C7H5N3O6/c1-4-6(9(13)14)2-5(8(11)12)3-7(4)10(15)16/h2-3H,1H3',
  'stdinchikey': 'SPSSULHKWOKEEL-UHFFFAOYSA-N'
}
```

after:

```json
{
  'inchi': 'InChI=1/C7H5N3O6/c1-4-6(9(13)14)2-5(8(11)12)3-7(4)10(15)16/h2-3H,1H3',
  'smiles': '[N+](=O)([O-])C1=C(C)C(=CC(=C1)[N+](=O)[O-])[N+](=O)[O-]',
  'status': 'SUCCESS',
  'stdinchi': 'InChI=1S/C7H5N3O6/c1-4-6(9(13)14)2-5(8(11)12)3-7(4)10(15)16/h2-3H,1H3',
  'stdinchikey': 'SPSSULHKWOKEEL-UHFFFAOYSA-N'
}
```