Remove tensorflow1.x dependency

[carankt]

Hey,
I have made the following changes, which helped me work better with the repository. Hoping it would do the same for others.

• Removed the tensorflow1.x dependency
• Created a .yaml config file in place of the hparams.py file
• implemented the changes for training and inference code

Best,
KT

[lgtm-com]

This pull request introduces 2 alerts when merging 9f285fe into 185cd24 - view on LGTM.com

new alerts:

• 1 for Missing call to __init__ during object initialization
• 1 for First argument to super() is not enclosing class

[sabard]

pyyaml package is also required here