Move database into the main app

I was having issues including the lib as a crate, its fine just being a
module for now.

migrations/2020-07-08-000046_setup_auth/down.sql

@@ -0,0 +1 @@
+DROP TABLE users

migrations/2020-07-08-000046_setup_auth/up.sql

@@ -0,0 +1,5 @@
+CREATE TABLE users (
+    id INTEGER PRIMARY KEY NOT NULL,
+    username TEXT NOT NULL,
+    password TEXT NOT NULL
+)