I had the problem that some of my PDF files had a Creation Date according to the american date format.
pdf_info should handle this case.
In the first step, it tries to parse it according to the american format. If this also fails, it just returns nil.
I also used the opportunity to
foo : bar
Require 'date' unless DateTime is already defined
Catch errors when parsing dates
Strips whitespace from metadata pair
Add some more specs for process_output method
Thanks! I rebased and merged this.