Not quite functional implementation of tox testing

I was able to get all but ~12 tests working locally by upgrading the version of Selenium and geckodriver along with these changes. I'm not sure if the remaining tests are breaking due to the Firefox/Selenium upgrade or something else, but maybe this can be a starting point if someone else wants to pick up the work.

.gitignore

@@ -10,3 +10,4 @@
 .idea/*
 dump.rdb
 problem_builder.tests.*
+.tox/

circle.yml

@@ -3,16 +3,6 @@ machine:
     version: 2.7.10
 dependencies:
   override:
-    - "pip install -U pip wheel"
-    # Temporarily pin setuptools to a specific version.
-    # See commit message of https://github.com/open-craft/problem-builder/commit/51277a34fb426724616618c1afdb893ab2de4c6b for more info:
-    - "pip install setuptools==24.3.1"
-    - "pip install -e git://github.com/edx/xblock-sdk.git@bddf9f4a2c6e4df28a411c8f632cc2250170ae9d#egg=xblock-sdk"
-    - "pip install -r requirements.txt"
-    - "pip install -r $VIRTUAL_ENV/src/xblock-sdk/requirements/base.txt"
-    - "pip install -r $VIRTUAL_ENV/src/xblock-sdk/requirements/test.txt"
-    - "pip uninstall -y xblock-problem-builder && python setup.py sdist && pip install dist/xblock-problem-builder-*.tar.gz"
-    - "pip install -r test_requirements.txt"
     - "mkdir var"
 test:
   override:
@@ -20,7 +10,12 @@ test:
         parallel: true
     - "if [ $CIRCLE_NODE_INDEX = '1' ]; then pylint problem_builder --disable=all --enable=function-redefined,undefined-variable,unused-import,unused-variable; fi":
         parallel: true
-    - "python run_tests.py":
+    - "tox -e py27-django18":
+        parallel: true
+        files:
+          - "problem_builder/v1/tests/**/*.py"
+          - "problem_builder/tests/**/*.py"
+    - "tox -e py27-django111":
         parallel: true
         files:
           - "problem_builder/v1/tests/**/*.py"

test_requirements.txt

--e git+https://github.com/edx/XBlock.git@tag-master-2015-05-22#egg=XBlock
-selenium==2.47.3  # 2.48 is not working atm
+#selenium==3.5.0
+fs<2
+xblock>0.5.0

tox.ini

+[tox]
+envlist = py{27}-django{18,111}
+
+# The ordering of deps and commands here is weird due to the way we install xblock-sdk and associated dependencies.
+# Installing test/base.txt inside deps fails, and installing the env-specific Django versions inside deps
+# causes Django 1.4 to be installed over it by something later in the process.
+[testenv]
+passenv = CI TRAVIS TRAVIS_* DISPLAY
+deps =
+    -egit+https://github.com/edx/xblock-sdk.git#egg=xblock-sdk
+commands =
+    pip install -r {envdir}/src/xblock-sdk/requirements/base.txt
+    pip install -r {envdir}/src/xblock-sdk/requirements/test.txt
+    pip install -r requirements.txt
+    pip install -r test_requirements.txt
+    django18: pip install Django>=1.8,<1.9
+    django110: pip install Django>=1.10,<1.11
+    django111: pip install Django>=1.11,<2.0
+    pip freeze
+    python ./run_tests.py