Add Dashboard Python Test to Buildkite (#13530)

.buildkite/Dockerfile

@@ -7,6 +7,7 @@ ENV DEBIAN_FRONTEND=noninteractive
 ENV TZ=America/Los_Angeles
 ENV BUILDKITE=true
 ENV CI=true
+ENV PYTHON=3.6
 
 RUN apt-get update -qq
 RUN apt-get install -y -qq \
@@ -25,4 +26,4 @@ WORKDIR /ray
 # Below should be re-run each time
 COPY . .
 RUN ./ci/travis/ci.sh init
-RUN ./ci/travis/ci.sh build
+RUN bash --login -i ./ci/travis/ci.sh build

.buildkite/pipeline.yml

@@ -1,3 +1,6 @@
 - label: "Ray Core Tests (:buildkite: Experimental)"
   commands:
   - bazel test --config=ci $(./scripts/bazel_export_options) --build_tests_only -- //:all -rllib/...
+- label: "Ray Dashboard Tests"
+  commands:
+  - bazel test --config=ci $(./scripts/bazel_export_options) python/ray/new_dashboard/...

ci/travis/install-dependencies.sh

@@ -216,8 +216,10 @@ install_upgrade_pip() {
 }
 
 install_node() {
-  if [ "${OSTYPE}" = msys ]; then
+  if [ "${OSTYPE}" = msys ] ; then
     { echo "WARNING: Skipping running Node.js due to incompatibilities with Windows"; } 2> /dev/null
+  elif [ -n "${BUILDKITE-}" ] ; then
+    { echo "WARNING: Skipping running Node.js on buildkite because it's already there"; } 2> /dev/null
   else
     # Install the latest version of Node.js in order to build the dashboard.
     (