Add an partial failure error handling example. (#77)
Add an partial failure error handling example. (#77)

* Add an partial failure error handling example.

Output looks like:

```
Created ad group criterion with id customers/blah/adGroupCriteria/blah
Created ad group criterion with id customers/blah/adGroupCriteria/blah
error occured creating criterion operations[1] > create > keyword > text with value: inv@lid cruise because keyword text has invalid characters or symbols.
error occured creating criterion operations[3] > create > keyword > text with value: b(a)d keyword cruise because keyword text has invalid characters or symbols.
```

* Print indexes on success in partial failure example.

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