Miscellaneous Fixes (#1752)

* Update CHANGELOG 
* Add `registered_only` decorator
* Make team invites redirect to `/register` if you're unauthed

CTFd/utils/decorators/__init__.py

@@ -97,6 +97,29 @@ def authed_only(f):
     return authed_only_wrapper
 
 
+def registered_only(f):
+    """
+    Decorator that requires the user to have a registered account
+    :param f:
+    :return:
+    """
+
+    @functools.wraps(f)
+    def _registered_only(*args, **kwargs):
+        if authed():
+            return f(*args, **kwargs)
+        else:
+            if (
+                request.content_type == "application/json"
+                or request.accept_mimetypes.best == "text/event-stream"
+            ):
+                abort(403)
+            else:
+                return redirect(url_for("auth.register", next=request.full_path))
+
+    return _registered_only
+
+
 def admins_only(f):
     """
     Decorator that requires the user to be authenticated and an admin