Functional login and logout, login system should be fucntionally implemented.

Testing and polishing are next.

app/__init__.py

@@ -1,4 +1,5 @@
 from flask import Flask
+import os
 from flask_sqlalchemy import SQLAlchemy
 from flask_login import LoginManager
 
@@ -8,8 +9,11 @@ login_manager = LoginManager()
 def create_app():
     app = Flask(__name__)
 
-    app.config["SQLALCHEMY_DATABASE_URI"] = ""
+    BASE_DIR = os.path.abspath(os.path.dirname(__file__))
+
+    app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///" + os.path.join(BASE_DIR, "app.db")
     app.config["SECRET_KEY"] = "dev-secret-key"
+    app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
 
     db.init_app(app)
     login_manager.init_app(app)
@@ -17,6 +21,9 @@ def create_app():
 
     from .models.user import User
 
+    with app.app_context():
+        db.create_all()
+
     @login_manager.user_loader
     def load_user(user_id):
         return db.session.get(User, int(user_id))