Fixes all the issues currently affecting the head detection demo

[IAmSuyogJadhav]

Specifically.

• Fixed Error when running demo #22 , also added instructions in the README.
• Fixed Bounding Boxes displacement error #15 , Applied the necessary changes directly in the code.
• Added instructions in the README to prevent ConnectionRefusedError #27 (ConnectionRefusedError)

Tested the code to work correctly on Ubuntu 18.04

[Vladimir-125]

Had the same issues with the config.py file. @aditya-vora please confirm the pull request.

Worth mentioning also that it would be great to add a requirements.txt file with the following packages:

scikit-image
torchnet
matplotlib
opencv-python