Update to Python 3 + small improvements

[Lau1406]

I found this repo quite useful to generate a arff file. But I also saw that it was quite old, so I tried to improve it, hope you don't mind.
Changes I made:

• I changed the code to work with Python 3
• Added an args parser to run it more easily with different input/output files
• Removed the sleep() parts
• Update the code style to pep8
• Added the option to choose the delimiter in the csv file