Test with Python 3.8 (and drop support for 3.4)

.travis.yml

@@ -1,10 +1,10 @@
 language: python
 python:
   - "2.7"
-  - "3.4"
   - "3.5"
   - "3.6"
   - "3.7"
+  - "3.8"
 cache: pip
 dist: xenial
 # command to install dependencies
@@ -27,4 +27,4 @@ deploy:
     script: .github/deploy.sh
     on:
       branch: master
-      python: 3.7
+      python: 3.8

Jenkinsfile

@@ -1,5 +1,6 @@
 def pys = [
-    [name: 'Python 3.7', docker:'python:3.7-buster', tox:'py37,flake8', main: true],
+    [name: 'Python 3.8', docker:'python:3.8-buster', tox:'py38,flake8', main: true],
+    [name: 'Python 3.7', docker:'python:3.7-buster', tox:'py37', main: false],
     [name: 'Python 3.6', docker:'python:3.6-buster', tox:'py36', main: false],
     [name: 'Python 3.5', docker:'python:3.5-buster', tox:'py35', main: false],
     [name: 'Python 2.7', docker:'python:2.7-buster', tox:'py27', main: false]

README.md

@@ -67,7 +67,7 @@ For advanced options and features execute `dosage --help`.
 ## Dependencies
 
 [Python](http://www.python.org/): for Python 2.x at least 2.7.0, for Python 3.x
-at least Python 3.4. Dosage requires the following Python modules:
+at least Python 3.5. Dosage requires the following Python modules:
 
 - colorama
 - lxml

setup.cfg

@@ -19,10 +19,10 @@ classifier =
     Programming Language :: Python :: 2
     Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.4
     Programming Language :: Python :: 3.5
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
     Operating System :: OS Independent
 
 [files]

setup.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 # Copyright (C) 2004-2008 Tristan Seligmann and Jonathan Jacobs
 # Copyright (C) 2012-2014 Bastian Kleineidam
-# Copyright (C) 2015-2018 Tobias Gruetzmacher
+# Copyright (C) 2015-2019 Tobias Gruetzmacher
 
 from __future__ import absolute_import, division, print_function
 
@@ -10,6 +10,6 @@ from setuptools import setup
 
 setup(
     setup_requires=['pbr>=1.9', 'setuptools>=17.1'],
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*',
     pbr=True,
 )

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27, py34, py35, py36, py37, flake8
+envlist = py27, py35, py36, py37, py38, flake8
 
 [testenv]
 commands =