build: Restore ember build/test on travis

Author: kamilogorek

scripts/test.sh

@@ -6,15 +6,19 @@ source ~/.nvm/nvm.sh
 if [[ "$(cut -d. -f1 <<< "$TRAVIS_NODE_VERSION")" -le 6 ]]; then
   nvm use 8
   yarn install --ignore-engines --ignore-scripts
+  # ember requires Node >= 10 to build
   yarn build --ignore="@sentry/ember"
   nvm use 6
-  yarn test --ignore="@sentry/browser" --ignore="@sentry/integrations" --ignore="@sentry/react" --ignore="@sentry/ember" --ignore="@sentry/tracing" # latest version of karma doesn't run on node 6
+  # browser can be tested only on Node >= v8 because Karma is not supporting anything older
+  yarn test --ignore="@sentry/browser" --ignore="@sentry/integrations" --ignore="@sentry/react" --ignore="@sentry/ember" --ignore="@sentry/tracing"
 elif [[ "$(cut -d. -f1 <<< "$TRAVIS_NODE_VERSION")" -le 8 ]]; then
   yarn install --ignore-engines --ignore-scripts
+  # ember requires Node >= 10 to build
   yarn build --ignore="@sentry/ember"
+  # tracing, ember and react work only on Node >= v10
   yarn test --ignore="@sentry/tracing" --ignore="@sentry/react" --ignore="@sentry/ember"
 else
   yarn install
-  yarn build --ignore="@sentry/ember"
-  yarn test --ignore="@sentry/ember"
+  yarn build
+  yarn test
 fi