#61 add support to shallow param

[rodolphopivetta]

I just added the param to shallow results

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[rodolphopivetta]

Google CLA account created

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CLAs look good, thanks!

[rodolphopivetta]

Failed test solved in commit rodolphopivetta@3bc92f4 but the PR did not update

[hiranya911]

Thanks @rodolphopivetta

Please fix the linter error detected by CI: https://travis-ci.org/firebase/firebase-admin-python/builds/289052233. You can run ./lint.sh all locally to see what the output is like.

And please provide unit tests (at leasts), and integration tests to verify the new functionality.

[hiranya911]

Thanks @rodolphopivetta. Implementation looks good. If you can provide at least a unit test, I can accept this PR. I can take care of updating the integration tests.

[rodolphopivetta]

I'll asap @hiranya911. Thanks

[hiranya911]

Closing in favor of #109. Thanks @rodolphopivetta for the contribution.