JUnit Report in Rust

Generate JUnit compatible XML reports in Rust.

Example

```rust

extern crate junit_report;

use junit_report::{Report, TestCase, TestSuite, Duration, TimeZone, Utc};
use std::str;


let timestamp = Utc.ymd(1970, 1, 1).and_hms(0, 1, 1);

let mut r = Report::new();
let mut ts1 = TestSuite::new("ts1");
ts1.set_timestamp(timestamp);
let mut ts2 = TestSuite::new("ts2");
ts2.set_timestamp(timestamp);

let test_success = TestCase::success("good test", Duration::seconds(15));
let test_error = TestCase::error(
    "error test",
    Duration::seconds(5),
    "git error",
    "unable to fetch",
);
let test_failure = TestCase::failure(
    "failure test",
    Duration::seconds(10),
    "assert_eq",
    "not equal",
);

ts2.add_testcase(test_success);
ts2.add_testcase(test_error);
ts2.add_testcase(test_failure);

r.add_testsuite(ts1);
r.add_testsuite(ts2);

let mut out: Vec<u8> = Vec::new();

r.write_xml(&mut out).unwrap();

```