Feature: Add python 3.7 and 3.8 and remove tests for 3.4
Feature: Add python 3.7 and 3.8 and remove tests for 3.4

pinry/pinry,lapo-luchini/pinry,lapo-luchini/pinry,lapo-luchini/pinry,lapo-luchini/pinry,pinry/pinry,pinry/pinry,pinry/pinry