Tableau server added few connectors now. Please wait for new version and get some new one.
Tableau web authoring supports connecting to your data through Tableau Online and Tableau Server using the following connectors:
Amazon Aurora Google Cloud SQL PostgreSQL Amazon Redshift MemSQL Snowflake Denodo Microsoft SQL Server Vertica EXASOL MySQL
If your site is in Tableau Server, you may see more connectors than are on this list.
Can you see AWS Athena connector at Tableau Prep 2018.3?
I can't. Where did you find it?