Allow intergration tests to test components

So a network request isn't created in tests respond with a predefined
html block.

Create a capybara test helper which asserts that that component is
present on the page.

The testing of the component and how it responds with different
arguments can be tested where the template exists. There is also a
further bit of work to create a intergration suit which will confirm
it runs correctly in preview/production.
Test the thing