Crate fails to build with `default-features = false`

[ktff]

Description

testcontainer will fail to build if all features are disabled like testcontainers = { version = "0.24", default-features = false }.

The build error:

testcontainers-0.24.0/src/core/client/bollard_client.rs:38:13
    |
38  |     Docker::connect_with_ssl(
    |             ^^^^^^^^^^^^^^^^ function or associated item not found in `Docker`

Temporary fix

Enable ring feature.