Make it take command line arguments

[prashantsengar]

I would like it to take command line arguments so that it can be run easily from the terminal like

python clean.py --weak PATH_TO_DIRECTORY

The arguments that it can support are

1. --weak for weak arrange
2. --strong for strong arrange (only one of the above two)
   2.1. --no-warning to not show any warning while running strong arrange (Remember, we warn people before running strong arrange)