When a compose is started the api call is no longer handled by the
CreateImageWizard onSave function. Instead, the CreateImageWizard
calls the composeStart thunk. This function calls the api and handles
the response. If successful, the compose is added to the store.
Otherwise, an error is added to the store.
The store's compose object now has a list of the compose ids and an
object containing key/value pairs mapping a compose id to the compose
for all composes. This "normalized" state will allow more efficiency
when selecting individual composes or iterating through all composes.
The compose objects in the store now match the composeRequest object
instead of having a shape unique to the UI. This can be changed in the
future if image-builder's api returns compose objects of a different
format.
Tests are updated for new compose format and action/reducer types.
Our compose actions will follow the naming convention of *name*_*event*.
Therefore, when we receive an updated compose from the api, the action
should be called COMPOSE_UPDATED.
The redux reducers and actions are moved to subdirectories within the
store directory. The goal of this is to improve the understandability of
the directory structure and to prepare for future scaling of the actions
and reducers.
As mentioned in the previous commit, `<Main>` doesn't really
belong in App.js, it instead belongs in LandingPage.js, because
it creates the html/css wrapper for the main contents, as a
sibling to the `<PageHeader>` component used in LandingPage.js.
However, including `<Main>` in LandingPage.js will cause the
tests to fail. Therefore, just the html and classes that
`<Main>` creates is used in LandingPage.js.
