Update dependency google-cloud-datastore to v1.13.1 (#4295)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [google-cloud-datastore](https://togithub.com/googleapis/python-datastore) | patch | `==1.13.0` -> `==1.13.1` |

---

### Release Notes

<details>
<summary>googleapis/python-datastore</summary>

### [`v1.13.1`](https://togithub.com/googleapis/python-datastore/blob/master/CHANGELOG.md#&#8203;1131-httpswwwgithubcomgoogleapispython-datastorecomparev1130v1131-2020-07-13)

[Compare Source](https://togithub.com/googleapis/python-datastore/compare/v1.13.0...v1.13.1)

</details>

---

### Renovate configuration

:date: **Schedule**: At any time (no schedule defined).

:vertical_traffic_light: **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

:recycle: **Rebasing**: Renovate will not automatically rebase this PR, because other commits have been found.

:no_bell: **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#GoogleCloudPlatform/python-docs-samples).

Author: renovate-bot

appengine/flexible/datastore/requirements.txt

@@ -1,3 +1,3 @@
 Flask==1.1.2
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1
 gunicorn==20.0.4

appengine/standard_python3/building-an-app/building-an-app-2/requirements.txt

@@ -1,2 +1,2 @@
 Flask==1.1.2
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1

appengine/standard_python3/building-an-app/building-an-app-3/requirements.txt

@@ -1,4 +1,4 @@
 Flask==1.1.2
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1
 google-auth==1.19.0
 requests==2.24.0

appengine/standard_python3/building-an-app/building-an-app-4/requirements.txt

@@ -1,4 +1,4 @@
 Flask==1.1.2
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1
 google-auth==1.19.0
 requests==2.24.0

appengine/standard_python37/building-an-app/building-an-app-2/requirements.txt

@@ -1,2 +1,2 @@
 Flask==1.1.2
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1

appengine/standard_python37/building-an-app/building-an-app-3/requirements.txt

@@ -1,4 +1,4 @@
 Flask==1.1.2
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1
 google-auth==1.19.0
 requests==2.24.0

appengine/standard_python37/building-an-app/building-an-app-4/requirements.txt

@@ -1,4 +1,4 @@
 Flask==1.1.2
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1
 google-auth==1.19.0
 requests==2.24.0

blog/introduction_to_data_models_in_cloud_datastore/requirements.txt

@@ -1 +1 @@
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1

codelabs/flex_and_vision/requirements.txt

@@ -3,4 +3,4 @@ gunicorn==20.0.4; python_version > '3.0'
 gunicorn==19.10.0; python_version < '3.0'
 google-cloud-vision==1.0.0
 google-cloud-storage==1.29.0
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1

datastore/cloud-client/requirements.txt

@@ -1 +1 @@
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1

dlp/requirements.txt

@@ -1,5 +1,5 @@
 google-cloud-dlp==1.0.0
 google-cloud-storage==1.29.0
 google-cloud-pubsub==1.7.0
-google-cloud-datastore==1.13.0
+google-cloud-datastore==1.13.1
 google-cloud-bigquery==1.25.0