Add test RFI

[nrathaus]

To add a pytest I had to:

1. remove the pwn import being done inside request
2. Move the color into its own class this way the init_args is not called on import, rather on the init - at which point under the pytest it is filled with dummy data

The pytest I created starts a simple web server, and responds with the decoded base64 data if it sees that the page parameter is being passed the pages we use for attacking

This pytest's goal is to detect that the filenames are being provided

[nrathaus]

@hansmach1ne this is the first pytest, it required some more changes to the colors module - as it was calling the check_arguments which cannot be called from pytest (no arguments there...)

If this first pytest is ok, I will create more - this pytest helped me see a false negative (you already fixed), so it is proving to provide good feedback already