Add Python 3.5 testing support (#230)

This adds support for testing Python 3.5.

Author: dagwieers

.travis.yml

@@ -2,6 +2,7 @@ language: python
 
 python:
 - '2.7'
+- '3.5'
 - '3.6'
 - '3.7'
 - '3.8'

Makefile

@@ -1,4 +1,3 @@
-ENVS := flake8,py27,py36
 export PYTHONPATH := $(CURDIR)/lib:$(CURDIR)/test
 addon_xml := addon.xml
 
@@ -32,7 +31,7 @@ sanity: tox pylint language
 
 tox:
 	@echo -e "$(white)=$(blue) Starting sanity tox test$(reset)"
-	tox -q -e $(ENVS)
+	tox -q
 
 pylint:
 	@echo -e "$(white)=$(blue) Starting sanity pylint test$(reset)"

tox.ini

@@ -1,6 +1,7 @@
 [tox]
-envlist = py27,py36,py37,flake8
+envlist = py27,py35,py36,py37,py38,flake8
 skipsdist = True
+skip_missing_interpreters = True
 
 [testenv:flake8]
 commands =