Build webpack frontend files before collecting static files during te…

…sts.

Also adds the directories for collected static files and for webpack bundles
to .dockerignore so that they don't get copied into docker images and mask
build problems that will arise on Circle.

.dockerignore

@@ -5,3 +5,5 @@ __pycache__
 .vagrant
 Vagrantfile
 .cache
+webapp-django/node_modules
+webapp-django/static

docker/run_tests.sh

@@ -50,6 +50,7 @@ if [ "${USEPYTHON:-2}" == "2" ]; then
 
     # Collect static and then run py.test in the webapp
     pushd webapp-django
+    "${WEBPACK_BINARY}" --mode=production --bail
     python manage.py collectstatic --noinput
     "${PYTEST}"
     popd