Add tap-sleeper to MeltanoHub

Checklist

• Add a file in the appropriate folder (/taps or /targets). The name of the file should match the name of the tap. If there is already one, add a descriptor to the name such as -search.
• Add a png logo image in /assets/logos/<taps or targets>. The image name must match the YAML file name.
• Tag @tayloramurphy or @pnadolny13 to flag it for review. Or post to the hub channel on Meltano slack.

Reviewer Checklist

• Validate file against JSON Schema. https://www.jsonschema.net/home is an option.
• Build website locally and validate everything works.