Implementing the tox and travis

.gitignore

@@ -5,3 +5,4 @@
 build/
 dist/
 django_progressive_web_app.egg-info/
+.tox/

.travis.yml

@@ -0,0 +1,11 @@
+language: python
+python:
+  - "3.6"
+  - "3.7"
+env:
+  - DJANGO_VERSION=2.0
+install:
+  - pip install Django==$DJANGO_VERSION
+  - pip install tox-travis
+  - pip install -q -r requirements-dev.txt
+script: tox

requirements-dev.txt

@@ -1 +1,2 @@
 pypandoc==1.3.3
+tox==3.2.1

tox.ini

@@ -0,0 +1,12 @@
+[tox]
+envlist = py37-django{18,20}
+
+[testenv]
+commands = python runtests.py
+setenv =
+    DJANGO_SETTINGS_MODULE=tests.test_settings
+    PYTHONPATH={toxinidir}
+basepython =
+    py36: python3.6
+    py37: python3.7
+deps = django20: Django==2.0