Try and catch some basic release issues with requirements across versions.

tox.ini

@@ -3,15 +3,29 @@ envlist = py{26,27,34,py,py3}, docs, style
 
 
 [testenv]
-changedir = {envtmpdir}
 setenv =
     JSON_SCHEMA_TEST_SUITE = {toxinidir}/json
+whitelist_externals =
+    python2.7
+    sh
+    virtualenv
 commands =
-    py26: trial [] jsonschema
-    py{27,34,py,py3}: green [] jsonschema
+    py26: sh -c 'cd {envtmpdir}; {envbindir}/trial [] jsonschema'
+    py{27,34,py,py3}: {envbindir}/green [] jsonschema
 
     {envpython} -m doctest {toxinidir}/README.rst
-    py{26,27,34}: sphinx-build -b doctest {toxinidir}/docs {envtmpdir}/html
+    py{26,27,34}: {envbindir}/sphinx-build -b doctest {toxinidir}/docs {envtmpdir}/html
+
+    # Check to make sure that releases build and install properly
+    virtualenv --quiet --python=python2.7 {envtmpdir}/venv
+    {envtmpdir}/venv/bin/pip install --quiet wheel
+
+    {envtmpdir}/venv/bin/python {toxinidir}/setup.py --quiet bdist_wheel --dist-dir={envtmpdir}/wheel
+    sh -c '{envbindir}/pip install --quiet --upgrade --force-reinstall {envtmpdir}/wheel/jsonschema*.whl'
+
+    python2.7 {toxinidir}/setup.py --quiet sdist --dist-dir={envtmpdir}/sdist --format=gztar,zip
+    sh -c '{envbindir}/pip install --quiet --upgrade --force-reinstall {envtmpdir}/sdist/jsonschema*.tar.gz'
+    sh -c '{envbindir}/pip install --quiet --upgrade --force-reinstall {envtmpdir}/sdist/jsonschema*.zip'
 deps =
     -e{toxinidir}[format]