Add (very simple) spec for a ViewComponent component

- Add `ViewComponent::TestHelpers` to get the helper method `render_inline`
 - Use Capybara to expect some assertion

spec/components/example_component_spec.rb

@@ -0,0 +1,8 @@
+require "spec_helper"
+
+describe "ExampleComponent tests", type: :component do
+  it "displays the h1 with the given parameter" do
+    render_inline(ExampleComponent.new(title: "Hello")) { }
+    expect(page).to have_selector "h1", text: "Hello"
+   end
+end