Cannot handle spaces in filenames

[mbeynon-galois]

Merging two PDF files, one of which has spaces in the name:

backslash escaped on command line ...

$ unipdf merge output.pdf part1.pdf part\ two\ report.pdf
Could not merge the input files: open part: no such file or directory

enclosed in double quotes ...

$ unipdf merge output.pdf part1.pdf "part two report.pdf"
Could not merge the input files: open part: no such file or directory

I was forced to rename the input file to be "part_two_report.pdf" for it to work properly. This should be an easy fix to not assume filenames won't have spaces in the name.