[tools/ci] Support spec:cypress

- Install node for spec:cypress
- Do an app:cypress:ui:seed instead of update:ui

The app:cypress:ui:seed handles compiling assets, so that would be
duplicate work to run it twice.

tools/ci/before_install.sh

@@ -1,4 +1,4 @@
 # not spec, and not cross repo
-if [ "$TEST_SUITE" = "spec:javascript" -o "$TEST_SUITE" = "spec:jest" -o "$TEST_SUITE" = "spec:compile" ]; then
+if [ "$TEST_SUITE" = "spec:javascript" -o "$TEST_SUITE" = "spec:jest" -o "$TEST_SUITE" = "spec:compile" -o "$TEST_SUITE" = "spec:cypress" ]; then
   nvm install 12
 fi

tools/ci/before_script.sh

@@ -1,8 +1,13 @@
 # not spec, and not cross repo
-if [ "$TEST_SUITE" = "spec:javascript" -o "$TEST_SUITE" = "spec:jest" -o "$TEST_SUITE" = "spec:compile" ]; then
+if [ "$TEST_SUITE" = "spec:javascript" -o "$TEST_SUITE" = "spec:jest" -o "$TEST_SUITE" = "spec:compile" -o "$TEST_SUITE" = "spec:cypress" ]; then
   # make sure yarn is installed, in the right version
   bundle exec rake webpacker:check_yarn || npm install -g yarn
 
   # install & compile dependencies
   bundle exec rake update:ui
+
+  if [ "$TEST_SUITE" = "spec:cypress" ]; then
+    # run evm:compile_assets (and friends) if cypress
+    bundle exec rake app:cypress:ui:seed
+  fi
 fi