The vault container was a previous TUF implementation
(TUF initialization pypi#7488)

The new integration with RSTUF does not require this container.

Signed-off-by: Kairo de Araujo <[email protected]>

This commit adds the RSTUF services to the Warehouse infrastructure
for development and sets the minimum required to start RSTUF services.

It adds the RSTUF API, which is used later to integrate into Warehouse
and RSTUF Worker, which is responsible for computing the TUF metadata.

The RSTUF requires the Postgres and Redis.
Postgres stores the rstuf database used for TUF metadata computing.
Redis stores the task message queue between RSTUF API and Worker, task
backend result, and live settings between RSTUF services.

RSTUF shares the same Postgres and Redis in development environment
but has a specific setup to use its own Postgres database and Redis
database ID.

Postgresql URI
`RSTUF_SQL_SERVER=postgresql://postgres@db:5432/rstuf`

Redis DB Broker and Result is id 1
`RSTUF_BROKER_SERVER=redis://redis/1`
`RSTUF_REDIS_SERVER_DB_RESULT=1`

Redis DB for TUF repository settings is 2
`RSTUF_REDIS_SERVER_DB_REPO_SETTINGS=2`

This commit also includes TUF database creation in the Makefile
during the `make initdb`.

Signed-off-by: Kairo de Araujo <[email protected]>

Remove settings from rstuf-worker in docker-compose.yml

Signed-off-by: Kairo de Araujo <[email protected]>