fix tests

[ccciudatu]

cargo test --lib --all-features currently fails with:

error[E0308]: mismatched types
   --> src/sql/db_connection_pool/sqlitepool.rs:285:78
    |
285 |         let factory = SqliteConnectionPoolFactory::new(&db_name, Mode::File, None);
    |                       --------------------------------                       ^^^^ expected `Duration`, found `Option<_>`
    |                       |
    |                       arguments to this function are incorrect
    |
    = note: expected struct `std::time::Duration`
                 found enum `std::option::Option<_>`
note: associated function defined here
   --> src/sql/db_connection_pool/sqlitepool.rs:33:12
    |
33  |     pub fn new(path: &str, mode: Mode, busy_timeout: Duration) -> Self {
    |            ^^^                         ----------------------