Fix incorrect use of backslashes in path on windows
Fix incorrect use of backslashes in path on windows

Fixes #715

jupyter/jupyterlab,charnpreetsingh185/jupyterlab,charnpreetsingh185/jupyterlab,eskirk/jupyterlab,jupyter/jupyterlab,charnpreetsingh185/jupyterlab,eskirk/jupyterlab,eskirk/jupyterlab,TypeFox/jupyterlab,TypeFox/jupyterlab,TypeFox/jupyterlab,TypeFox/jupyterlab,eskirk/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab,charnpreetsingh185/jupyterlab,eskirk/jupyterlab,TypeFox/jupyterlab,jupyter/jupyterlab,charnpreetsingh185/jupyterlab