Fix bars_validity for market close

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

src/utils/time.rs

@@ -2,16 +2,13 @@ use std::time::Duration;
 use time::OffsetDateTime;
 
 pub const ONE_MINUTE: Duration = Duration::from_secs(60);
+pub const FIFTEEN_MINUTES: Duration = Duration::from_secs(60 * 15);
 
 pub fn last_minute() -> OffsetDateTime {
     let now_timestamp = OffsetDateTime::now_utc().unix_timestamp();
     OffsetDateTime::from_unix_timestamp(now_timestamp - now_timestamp % 60).unwrap()
 }
 
-pub fn next_minute() -> OffsetDateTime {
-    last_minute() + ONE_MINUTE
-}
-
 pub fn duration_until(time: OffsetDateTime) -> Duration {
     let duration = time - OffsetDateTime::now_utc();