add lastmodified in req props

src/utils/time.rs

@@ -0,0 +1,6 @@
+use chrono::{DateTime, TimeZone, Utc, ParseError};
+
+pub fn parse_timestamp(timestamp: &str) -> Result<DateTime<Utc>, ParseError> {
+    let format = "%a, %d %b %Y %H:%M:%S %Z";
+    Utc.datetime_from_str(timestamp, format)
+}