Handle case on home page where no channels exist in the export (#118)
Handle case on home page where no channels exist in the export (#118)

* minor modifications to handle input from https://github.com/zach-snell/slack-export where there is no public channel output to the archive

* taking into account feedback on DMs failing from saschamarkus

* incorporating feedback from hfaran to return response to client in the event that no parsable data is included in the zip file

hfaran/slack-export-viewer,hfaran/slack-export-viewer