Changes in version 0.1.2.9000                      

  - Adds n_min argument (default 1). Specifies the minimum number of
    plumber APIs always running. Previously, some requests might fail if
    all connections had gone stale and been pruned.
      - Valve will now always spawn the first connection automatically.
        Additional connections will be spawned on-demand. Once n_min has
        been reached, the number of connections will never be lower.