add high/low price query

Author: abrook7

sql/Redshift_queries.sql

@@ -15,4 +15,10 @@ SELECT
     volume_traded 
 FROM "mydb"."public"."bitcoin_prices" 
 ORDER BY volume_traded DESC
-LIMIT 1;
+LIMIT 1;
+
+--High and Low Price
+SELECT 
+    max(price_high), 
+    min(price_low) 
+FROM "mydb"."public"."bitcoin_prices";