A ContentsManager wrapper for using multiple ContentsManager in Jupyter
The HybridContentManager was originally created by Quantopian as part of pgcontents; however, the usage of HybridContentsManager was restricted to the compatibility requirements of pgcontents. These restrictions included postgres dependencies and no support for the latest notebook version (>6). At Viaduct we used pgcontents exclusively for the HybridContentsManager and wanted to extend its functionality, so we created this fork hybridcontents.