Db, add core user functionality and tests; db mod

Adds all the basic user functions, and tests for them.

This is also intializes the DB Module, which will have more things in it

koucha/src/test_utils.rs

@@ -1,11 +1,24 @@
 #![cfg(test)]
 
+use crate::{
+  Adapter,
+  AdapterBuilder,
+};
 use chrono::{
   Utc,
   TimeZone,
   DateTime
 };
 
+pub const USERNAME: &str = "Alice";
+pub const USERNAME2: &str = "Bob";
+
 pub fn get_datetime() -> DateTime<Utc> {
   Utc.with_ymd_and_hms(2020,1,1,0,0,0).unwrap()
 }
+
+pub async fn setup_adapter() -> Adapter {
+  AdapterBuilder::new()
+    .database_url("sqlite::memory:")
+    .create().await.unwrap()
+}