Add `base_url` when loading CSS
Add `base_url` when loading CSS

original-commit-id: 47843058e9fce63fe7c9dcd5eb37b8d30deaa14c
original-commit-url: https://github.com/ipython-contrib/IPython-notebook-extensions/commit/47843058e9fce63fe7c9dcd5eb37b8d30deaa14c

jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator