Updates for the repository

[Vladkryvoruchko]

[Created Issue for tracking]
Disclaimer: I know there are several repos on the Github, that already include PSPNet implemented in TensorFlow with all the features included, but aint give a shit about that, just want to help anyone who use this repo, and know that I have a high-quality code.

Alright, I haven't maintained anything here for a while, so its time to put some effort to solve as many issues as I can and upgrade repo to the:

• fix high-severity bugs
• latest Python/dependencies version
• Remove deprecated methods
• Optimize code
• Add some tests
• Maybe add some better deploy experience
• Add API layer(?)

I plan to deliver updates in several phases:

• Write some simple smoke tests, to be sure system functioning
  Merged PRs: Feat/tests #74

• Resolve any issues that are related to the bugfix/performance/optimization using Python3.5 interpreter
  Merged PRs: Remove unnecessary resizing #58 performance improvement with np and cv2; Fixes #26 #37 Upgrade to new versions / Optimizations / Bug fixes #70 Bugfixes #1 #71 Bugfixes #2 #72 Upgrade to new versions / Optimizations / Bug fixes #73

• Remove blockers to be able to upgrade to the latest stable Python/TF/Keras versions
  Add support for Python3.4+, instead of some fixed version of interpreter

• I expect to have a bunch of new issues after upgrading to the new versions, so then will be the phase of solving new issues.

• Look and analyze Make PSPNet Fully-convolutional #41 (Make PSPNet fully convolutional)

• Refactor code OOP, structure(library API layer, CLI layer,).

• Create better logging

• Add evaluation script

• Upgrade training script

• Answer the most common questions in the READme, so fewer issues with common questions will be created

• (Different repository) Create Flask API wrapper around this project to ease up deploy/integration/whatever, so ppl without related experience can run it as easy as count to 3 e.g: git pull, make build; make deploy;
  then do simple http(s) request
  (docker-compose/Flask/nginx/uwsgi(or gunicorn)/celery worker/redis[or whatever configurable queue])