String to seconds
(Swift version of sec)
XCTAssertEqual("00:00:05".toSeconds, 5)
XCTAssertEqual("00:01:00".toSeconds, 60)
XCTAssertEqual("01:01:01".toSeconds, 3661)
XCTAssertEqual("01:00".toSeconds, 60)
XCTAssertEqual("01".toSeconds, 1)
XCTAssertEqual("1".toSeconds, 1)