AzureClipStorage breaks if one directory name is prefix of another #52

AzureClipStorage currently lists clips by getting all files where the file name starts with a certain string:

If there are two directories named "something/xyz" and "something/xyz_abc", then this will cause the script to also enumerate files from the second directory when looking for files from the first (which causes the script to crash). While easy to work around, this seems unintended, and should probably be changed.