Bump boto3 from 1.19.12 to 1.20.4 (#89)

Bumps [boto3](https://github.com/boto/boto3) from 1.19.12 to 1.20.4.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/boto/boto3/blob/develop/CHANGELOG.rst">boto3's changelog</a>.</em></p>
<blockquote>
<h1>1.20.4</h1>
<ul>
<li>api-change:<code>dynamodb</code>: [<code>botocore</code>] Updated Help section for &quot;dynamodb update-contributor-insights&quot; API</li>
<li>api-change:<code>ec2</code>: [<code>botocore</code>] This release provides an additional route target for the VPC route table.</li>
<li>api-change:<code>translate</code>: [<code>botocore</code>] This release enables customers to import Multi-Directional Custom Terminology and use Multi-Directional Custom Terminology in both real-time translation and asynchronous batch translation.</li>
</ul>
<h1>1.20.3</h1>
<ul>
<li>api-change:<code>backup</code>: [<code>botocore</code>] AWS Backup SDK provides new options when scheduling backups: select supported services and resources that are assigned to a particular tag, linked to a combination of tags, or can be identified by a partial tag value, and exclude resources from their assignments.</li>
<li>api-change:<code>ecs</code>: [<code>botocore</code>] This release adds support for container instance health.</li>
<li>api-change:<code>resiliencehub</code>: [<code>botocore</code>] Initial release of AWS Resilience Hub, a managed service that enables you to define, validate, and track the resilience of your applications on AWS</li>
</ul>
<h1>1.20.2</h1>
<ul>
<li>api-change:<code>batch</code>: [<code>botocore</code>] Adds support for scheduling policy APIs.</li>
<li>api-change:<code>health</code>: [<code>botocore</code>] Documentation updates for AWS Health.</li>
<li>api-change:<code>greengrassv2</code>: [<code>botocore</code>] This release adds support for Greengrass core devices running Windows. You can now specify name of a Windows user to run a component.</li>
</ul>
<h1>1.20.1</h1>
<ul>
<li>bugfix:urllib3: [<code>botocore</code>] Fix NO_OP_TICKET import bug in older versions of urllib3</li>
</ul>
<h1>1.20.0</h1>
<ul>
<li>feature:EndpointResolver: [<code>botocore</code>] Adding support for resolving modeled FIPS and Dualstack endpoints.</li>
<li>feature:<code>six</code>: [<code>botocore</code>] Updated vendored version of <code>six</code> from 1.10.0 to 1.16.0</li>
<li>api-change:<code>sagemaker</code>: [<code>botocore</code>] SageMaker CreateEndpoint and UpdateEndpoint APIs now support additional deployment configuration to manage traffic shifting options and automatic rollback monitoring. DescribeEndpoint now shows new in-progress deployment details with stage status.</li>
<li>api-change:<code>chime-sdk-meetings</code>: [<code>botocore</code>] Updated format validation for ids and regions.</li>
<li>api-change:<code>wafv2</code>: [<code>botocore</code>] You can now configure rules to run a CAPTCHA check against web requests and, as needed, send a CAPTCHA challenge to the client.</li>
<li>api-change:<code>ec2</code>: [<code>botocore</code>] This release adds internal validation on the GatewayAssociationState field</li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/boto/boto3/commit/ca177e6242a4e6c73ffd165242d21e131970d3ca"><code>ca177e6</code></a> Merge branch 'release-1.20.4'</li>
<li><a href="https://github.com/boto/boto3/commit/f4233c12d229f13af7851b776e22faac8f857795"><code>f4233c1</code></a> Bumping version to 1.20.4</li>
<li><a href="https://github.com/boto/boto3/commit/bca7e0288aef514bb767842906685ced883570e2"><code>bca7e02</code></a> Add changelog entries from botocore</li>
<li><a href="https://github.com/boto/boto3/commit/684da6219557f3791bedb936849cd26706c93853"><code>684da62</code></a> Add maintenance notice to README (<a href="https://github-redirect.dependabot.com/boto/boto3/issues/3068">#3068</a>)</li>
<li><a href="https://github.com/boto/boto3/commit/2dd556248c07b00e1769cd59dcedef359076a795"><code>2dd5562</code></a> Merge branch 'release-1.20.3'</li>
<li><a href="https://github.com/boto/boto3/commit/70e6f6ce7dbf462cefcd2123e5990e26c783b824"><code>70e6f6c</code></a> Merge branch 'release-1.20.3' into develop</li>
<li><a href="https://github.com/boto/boto3/commit/e57f5ec29079d2ef67f2673869f8625611e59ee4"><code>e57f5ec</code></a> Bumping version to 1.20.3</li>
<li><a href="https://github.com/boto/boto3/commit/e8722f68b94ad45935ae490452138d036314f1bd"><code>e8722f6</code></a> Add changelog entries from botocore</li>
<li><a href="https://github.com/boto/boto3/commit/3c1049bcfc24e62e5ffd90f11809e9c3ffddd7a9"><code>3c1049b</code></a> Merge branch 'release-1.20.2'</li>
<li><a href="https://github.com/boto/boto3/commit/359aa3158df4f5f7e54fbfa60d31a777f63eb688"><code>359aa31</code></a> Merge branch 'release-1.20.2' into develop</li>
<li>Additional commits viewable in <a href="https://github.com/boto/boto3/compare/1.19.12...1.20.4">compare view</a></li>
</ul>
</details>
<br />


[![Dependabot compatibility score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=boto3&package-manager=pip&previous-version=1.19.12&new-version=1.20.4)](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores)

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
- `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)


</details>