Merge pull request #134 from adbar/patch-1

Extended travis config:
 - Python versions added (3.9, pypy)
 - OS added (MacOS, 2 different versions)

.travis.yml

@@ -1,15 +1,57 @@
 language: python
+os: linux
+cache: pip
 
-python:
-  - 2.7
-  - 3.5
-  - 3.6
-  - 3.7
-  - 3.8
+matrix:
+  include:
+    - name: "Python 2.7 on Linux"
+      python: 2.7
+      env: PIP=pip
+    - name: "Python 3.5 on Linux"
+      python: 3.5
+    - name: "Python 3.6 on Linux"
+      python: 3.6
+    - name: "Python 3.7 on Linux"
+      python: 3.7
+    - name: "Python 3.8 on Linux"
+      dist: xenial
+      python: 3.8
+    - name: "Python 3.9 Nightly on Linux"
+      dist: bionic
+      python: nightly
+    - name: "Pypy on Linux"
+      python: pypy
+      env: PIP=pip
+    - name: "Pypy 3 on Linux"
+      python: pypy3
+    - name: "Python 3.7 on older macOS"
+      os: osx
+      osx_image: xcode9.4
+      language: shell
+      env: TOXENV=py37
+      before_install:
+        - sw_vers
+        - python3 --version
+        - pip3 --version
+    - name: "Python 3.7 on macOS"
+      os: osx
+      osx_image: xcode11
+      language: shell
+      env: TOXENV=py37
+      before_install:
+        - sw_vers
+        - python3 --version
+        - pip3 --version
+  allow_failures:
+    - python: nightly
+    - python: pypy
+    - python: pypy3
+    - os: osx
 
 install:
-  - travis_retry pip install -U pip wheel tox-travis
-  - travis_retry pip install -U -r requirements.txt -e ".[test]"
+  - if [ $PIP ]; then true; else PIP=pip3; fi
+  - travis_retry $PIP install -U pip wheel tox-travis
+  - travis_retry $PIP install -U -r requirements.txt -e ".[test]"
 
 script:
   - tox

tox.ini

@@ -4,7 +4,10 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py27, py35, py36, py37, py38, doc
+envlist =
+    py{27,35,36,37,38,py,py3}, doc
+skip_missing_interpreters =
+    True
 
 [testenv]
 deps =
@@ -19,7 +22,8 @@ deps =
 # requires a Compiler and the build dependencies), you can download
 # it from http://www.lfd.uci.edu/~gohlke/pythonlibs/#lxml and install it via
 # $PYTHONDIR\Scripts\pip.exe install *.whl
-sitepackages=True
+sitepackages=
+    True
 commands =
     pip install -r requirements.txt -e ".[test]"
     py.test