Update README.md
[FEATURE] Added additional required packages in requirements.txt
Merge pull request #556 from Ignat99/feature

[FEATURE] Added additional required packages in requirements.txt
DHT._dataStore -> DHT.dataStore
DHT/Transport refactors, updates.

 - DHT on_find_node DRY refactors.
 - TransportLayer/CryptoTransportLayer now destroy ZMQ sockets on shutdown.
Remove contact in place (without rebuilding list).
Docstring fixes.
Just a list.
Honour import style.
Delegate removal to python. Avoid recreating list.

* Using list.remove means the element is removed
  in-place and no new list is created. This lessens
  the space requirements and may improve speed.
Simplify getContacts.
More docstring fixes.
Raise value error when removing non-existing contact.

Fix #535.
Enable due test.
Remove execute flag.
Wrap long line.