Upgrade to GitHub-native Dependabot

[dependabot-preview]

Dependabot Preview will be shut down on August 3rd, 2021. In order to keep getting Dependabot updates, please merge this PR and migrate to GitHub-native Dependabot before then.

Dependabot has been fully integrated into GitHub, so you no longer have to install and manage a separate app. This pull request migrates your configuration from Dependabot.com to a config file, using the new syntax. When merged, we'll swap out dependabot-preview (me) for a new dependabot app, and you'll be all set!

With this change, you'll now use the Dependabot page in GitHub, rather than the Dependabot dashboard, to monitor your version updates, and you'll configure Dependabot through the new config file rather than a UI.

If you've got any questions or feedback for us, please let us know by creating an issue in the dependabot/dependabot-core repository.

Learn more about migrating to GitHub-native Dependabot

Please note that regular @dependabot commands do not work on this pull request.

[codecov]

Codecov Report

Merging #257 (cc6af84) into master (5f4bf49) will not change coverage.
The diff coverage is n/a.

❗ Current head cc6af84 differs from pull request most recent head 6a43ccd. Consider uploading reports for the commit 6a43ccd to get more accurate results

@@           Coverage Diff           @@
##           master     #257   +/-   ##
=======================================
  Coverage   89.77%   89.77%           
=======================================
  Files          11       11           
  Lines         528      528           
  Branches      134      134           
=======================================
  Hits          474      474           
  Misses         54       54           

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[dependabot-preview]

As a reminder, Dependabot Preview will be shut down on August 3rd, 2021. You can merge this pull request to migrate to GitHub-native Dependabot. You can read the docs to learn more about what's changing, as well as find out how to get support if you need help migrating.