fixup! build: add option for running all component tests

Address feedback

Author: devversion

scripts/run-component-tests.js

@@ -74,8 +74,12 @@ if (all) {
 // Exit if no component has been specified.
 if (!components.length) {
   console.error(chalk.red(
-      'No component specified. Specify a component name, or pass a ' +
-      'path to the component directory.'));
+      'No component specified. Please either specify individual components, or pass the "--all" ' +
+      'flag in order to run tests for all components.'));
+  console.info(chalk.yellow('Below are a few examples of how the script can be run:'));
+  console.info(chalk.yellow(` - yarn test --all`));
+  console.info(chalk.yellow(` - yarn test src/cdk/button src/material/stepper`));
+  console.info(chalk.yellow(` - yarn test button toolbar`));
   process.exit(1);
 }