PDF does not contain EOF marker (PDF :: Reader :: MalformedPDFError) with PDF reader

I am using a "PDF reader" to read the original content of PDF documents so that I can http-post them to the API. To confirm that the API implementation can generate a valid PDF from the original content, I wrote a small gist to check my code to read the pdf content.

For some reason I always keep getting "PDF does not contain EOF marker (PDF :: Reader :: MalformedPDFError).

Can anyone point me where I am going wrong?