Use tox for testing.

.travis.yml

@@ -12,10 +12,9 @@ addons:
       - libjpeg-dev
 # command to install dependencies
 install:
-  - pip install -r requirements.txt
-  - pip install pytest-xdist pytest-cov pytest-travis-fold coveralls
+  - pip install pytest-travis-fold tox-travis coveralls
 # command to run tests
-script: make test PYTESTOPTS="--cov=dosage --cov=dosagelib --tb=short -n10"
+script: tox
 after_success:
       coveralls
 notifications:

setup.cfg

@@ -37,8 +37,6 @@ dimensions =
     Pillow
 bash =
     argcomplete
-test =
-    pytest-xdist
 
 [bdist_wheel]
 universal=1

tox.ini

@@ -0,0 +1,16 @@
+# Tox (http://tox.testrun.org/) is a tool for running tests
+# in multiple virtualenvs. This configuration file will run the
+# test suite on all supported python versions. To use it, "pip install tox"
+# and then run "tox" from this directory.
+
+[tox]
+envlist = py27, py35
+
+[testenv]
+commands = py.test --cov=dosage --cov=dosagelib --tb=short -n10
+# Also install optional dependencies for tests.
+deps =
+    pytest-xdist
+    pytest-cov
+    cssselect
+    Pillow