issue when use `beta_to_450k`

[axxxxx08]

Hi, thanks for developing this useful tool!

However, I had some problems when I wanted to convert my WGBS data to 850K array data, I trying to use beta_to_450k to do that, but there were some errors.

The command is:

~/software/wgbs_tools/wgbstools beta_to_450k -o test --EPIC ./PR10200180.sorted.beta

The warning message is:

Invalid input argument
Input file is None

Looking forward to your reply. Thanks!!