Use ?NNN format instead of ?

https://sqlite.org/lang_expr.html#parameters
> But because it is easy to miscount the question marks, the use of this parameter format is discouraged. Programmers are encouraged to use one of the symbolic formats below or the ?NNN format above instead.

src/types/time.rs

@@ -91,7 +91,7 @@ mod test {
         ts_vec.push(make_datetime(10_000_000_000, 0)); //November 20, 2286
 
         for ts in ts_vec {
-            db.execute("INSERT INTO foo(t) VALUES (?)", [ts])?;
+            db.execute("INSERT INTO foo(t) VALUES (?1)", [ts])?;
 
             let from: OffsetDateTime = db.one_column("SELECT t FROM foo")?;
 
@@ -143,7 +143,7 @@ mod test {
                 Ok(OffsetDateTime::parse("2013-10-07T04:23:19.120-04:00", &Rfc3339).unwrap()),
             ),
         ] {
-            let result: Result<OffsetDateTime> = db.query_row("SELECT ?", [s], |r| r.get(0));
+            let result: Result<OffsetDateTime> = db.query_row("SELECT ?1", [s], |r| r.get(0));
             assert_eq!(result, t);
         }
         Ok(())
@@ -160,7 +160,7 @@ mod test {
     #[test]
     fn test_param() -> Result<()> {
         let db = Connection::open_in_memory()?;
-        let result: Result<bool> = db.query_row("SELECT 1 WHERE ? BETWEEN datetime('now', '-1 minute') AND datetime('now', '+1 minute')", [OffsetDateTime::now_utc()], |r| r.get(0));
+        let result: Result<bool> = db.query_row("SELECT 1 WHERE ?1 BETWEEN datetime('now', '-1 minute') AND datetime('now', '+1 minute')", [OffsetDateTime::now_utc()], |r| r.get(0));
         result.unwrap();
         Ok(())
     }