cron 0.11.0

A cron expression parser and schedule explorer.
Documentation
# cron [![Rust]https://github.com/zslayton/cron/workflows/Rust/badge.svg]https://github.com/zslayton/cron/actions [![]https://img.shields.io/crates/v/cron.svg]https://crates.io/crates/cron [![]https://docs.rs/cron/badge.svg]https://docs.rs/cron
A cron expression parser. Works with stable Rust v1.28.0.

```rust
use cron::Schedule;
use chrono::Utc;
use std::str::FromStr;

fn main() {
  //               sec  min   hour   day of month   month   day of week   year
  let expression = "0   30   9,12,15     1,15       May-Aug  Mon,Wed,Fri  2018/2";
  let schedule = Schedule::from_str(expression).unwrap();
  println!("Upcoming fire times:");
  for datetime in schedule.upcoming(Utc).take(10) {
    println!("-> {}", datetime);
  }
}

/*
Upcoming fire times:
-> 2018-06-01 09:30:00 UTC
-> 2018-06-01 12:30:00 UTC
-> 2018-06-01 15:30:00 UTC
-> 2018-06-15 09:30:00 UTC
-> 2018-06-15 12:30:00 UTC
-> 2018-06-15 15:30:00 UTC
-> 2018-08-01 09:30:00 UTC
-> 2018-08-01 12:30:00 UTC
-> 2018-08-01 15:30:00 UTC
-> 2018-08-15 09:30:00 UTC
*/
```

## License

Licensed under either of
 * Apache License, Version 2.0 ([LICENSE-APACHE]LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
 * MIT license ([LICENSE-MIT]LICENSE-MIT or https://opensource.org/licenses/MIT)
at your option.

### Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you shall be dual licensed as above, without any
additional terms or conditions.