Rewrite default test:

This test will be used to update the code and, following that, the
rest of the tests will be corrected, if necessary.
there is no context anymore
you cannot call plugin_setting() lazily anymore
read from session object
check redirect better - it shouldn't have content either
another use of context
check for redirect better
save the url, use the redirected one
use entire path to get cookie data properly
check redirect better
whoops, changed this by mistake
check redirect better
all the fixes
another test
another test
Test mounted situation:

What happens when the app is actually mounted on a path?

$request->path() will reflect the full path, while
$request->path_info() will reflect the mounted path, which is what
we want, since the mounting will prefix the mounting point.
Fix mounting point:

When mounted on /auth, if we use the $request->path() method, the
return url will be set to /auth/auth/login.

When we use $request->path_info() method, the return url will
correctly be set to /auth/login instead.
Merge branch 'fix/v0.153002-update'