Enable dependabot to automatically get dependency updates

[MRamonLeon]

It would be great to have Dependabot configured to get dependencies updates filed automatically. This will help avoiding bugs or security vulnerabilities from old dependencies.

Some helpful documentation about Dependabot to fine adjust it if needed:

• Keeping your dependencies updated automatically: https://docs.github.com/en/free-pro-team@latest/github/administering-a-repository/keeping-your-dependencies-updated-automatically
• Avoiding security vulnerabilities: https://docs.github.com/en/free-pro-team@latest/github/managing-security-vulnerabilities/configuring-github-dependabot-security-updates
• Fine adjusting the configuration: https://docs.github.com/en/free-pro-team@latest/github/administering-a-repository/configuration-options-for-dependency-updates

[jglick]

EC2 agent flake. May need a rebuild after #43.

[jglick]

Going to try to trigger a new build merged with master.