- update: database client to implement a database trait so we can mock it out

- update unit tests
- add: database client mock

database-service/tests/redis_cache.rs

@@ -1,11 +1,13 @@
 use deadpool_redis::{Config, Pool, Runtime};
 use redis::AsyncCommands;
 use database_service::redis_cache::RedisCache;
+use dotenv::dotenv;
 
 #[tokio::test]
 async fn test_redis_cache() {
-    let redis_url = "redis://127.0.0.1:6379";
-    let cache = RedisCache::new(redis_url);
+    dotenv().ok();
+    let redis_url = std::env::var("REDIS_URL").unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
+    let cache = RedisCache::new(&redis_url);
 
     let key = &"test_key".to_string();
     let value = "test_value";