chore(deps): update dependency google-auth to v1.22.1 (#84)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [google-auth](https://togithub.com/googleapis/google-auth-library-python) | minor | `==1.21.0` -> `==1.22.1` |

---

### Release Notes

<details>
<summary>googleapis/google-auth-library-python</summary>

### [`v1.22.1`](https://togithub.com/googleapis/google-auth-library-python/blob/master/CHANGELOG.md#&#8203;1221-httpswwwgithubcomgoogleapisgoogle-auth-library-pythoncomparev1220v1221-2020-10-05)

[Compare Source](https://togithub.com/googleapis/google-auth-library-python/compare/v1.22.0...v1.22.1)

### [`v1.22.0`](https://togithub.com/googleapis/google-auth-library-python/blob/master/CHANGELOG.md#&#8203;1220-httpswwwgithubcomgoogleapisgoogle-auth-library-pythoncomparev1213v1220-2020-09-28)

[Compare Source](https://togithub.com/googleapis/google-auth-library-python/compare/v1.21.3...v1.22.0)

##### Features

-   add asyncio based auth flow ([#&#8203;612](https://www.github.com/googleapis/google-auth-library-python/issues/612)) ([7e15258](https://www.github.com/googleapis/google-auth-library-python/commit/7e1525822d51bd9ce7dffca42d71313e6e776fcd)), closes [#&#8203;572](https://www.github.com/googleapis/google-auth-library-python/issues/572)

##### [1.21.3](https://www.github.com/googleapis/google-auth-library-python/compare/v1.21.2...v1.21.3) (2020-09-22)

##### Bug Fixes

-   fix expiry for `to_json()` ([#&#8203;589](https://www.github.com/googleapis/google-auth-library-python/issues/589)) ([d0e0aba](https://www.github.com/googleapis/google-auth-library-python/commit/d0e0aba0a9f665268ffa1b22d44f4bd7e9b449d6)), closes [/github.com/googleapis/oauth2client/blob/master/oauth2client/client.py#L55](https://www.github.com/googleapis//github.com/googleapis/oauth2client/blob/master/oauth2client/client.py/issues/L55)

##### [1.21.2](https://www.github.com/googleapis/google-auth-library-python/compare/v1.21.1...v1.21.2) (2020-09-08)

##### Bug Fixes

-   migrate signBlob to iamcredentials.googleapis.com ([#&#8203;600](https://www.github.com/googleapis/google-auth-library-python/issues/600)) ([694d83f](https://www.github.com/googleapis/google-auth-library-python/commit/694d83fd23c0e8c2fde27136d1b3f8f6db6338a6))

##### [1.21.1](https://www.github.com/googleapis/google-auth-library-python/compare/v1.21.0...v1.21.1) (2020-09-03)

##### Bug Fixes

-   dummy commit to trigger a auto release ([#&#8203;597](https://www.github.com/googleapis/google-auth-library-python/issues/597)) ([d32f7df](https://www.github.com/googleapis/google-auth-library-python/commit/d32f7df4895122ef23b664672d7db3f58d9b7d36))

### [`v1.21.3`](https://togithub.com/googleapis/google-auth-library-python/blob/master/CHANGELOG.md#&#8203;1213-httpswwwgithubcomgoogleapisgoogle-auth-library-pythoncomparev1212v1213-2020-09-22)

[Compare Source](https://togithub.com/googleapis/google-auth-library-python/compare/v1.21.2...v1.21.3)

### [`v1.21.2`](https://togithub.com/googleapis/google-auth-library-python/blob/master/CHANGELOG.md#&#8203;1212-httpswwwgithubcomgoogleapisgoogle-auth-library-pythoncomparev1211v1212-2020-09-08)

[Compare Source](https://togithub.com/googleapis/google-auth-library-python/compare/v1.21.1...v1.21.2)

### [`v1.21.1`](https://togithub.com/googleapis/google-auth-library-python/blob/master/CHANGELOG.md#&#8203;1211-httpswwwgithubcomgoogleapisgoogle-auth-library-pythoncomparev1210v1211-2020-09-03)

[Compare Source](https://togithub.com/googleapis/google-auth-library-python/compare/v1.21.0...v1.21.1)

</details>

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bigquery_storage/to_dataframe/requirements.txt

@@ -1,4 +1,4 @@
-google-auth==1.21.0
+google-auth==1.22.1
 google-cloud-bigquery-storage==2.0.0
 google-cloud-bigquery==2.2.0
 pyarrow==1.0.1