add login/logout urls and templates

templates/registration/login.html

@@ -0,0 +1,9 @@
+{% extends 'base.html' %} 
+{% block title %}Login{% endblock %} 
+{% block body_content %}
+<h2>Login</h2>
+<form method="post">
+    {% csrf_token %} {{ form.as_p }}
+    <button type="submit">Login</button>
+</form>
+{% endblock %}