Missing engine:install:migrations task for plugin/engine --mountable (Rails 4.2.4)

[Dr. Jackanapes]

According to the Rails guides (http://guides.rubyonrails.org/engines.html), after creating an engine using --mountable, there should should be a rake task in the parent app (not the engine), in the format 

rake <engine>:install:migrations

for copying engine migrations from the Rails engine into the parent app. 

I've run through the tutorial in the guides twice and each time there is only the following rake task in the Rails engine (which copies the engine migrations into /test/dummy/db/migrate):

rake app:<engine>:install:migrations

Neither 

rake <engine>:install:migrations

nor 

rake railties:install:migrations

copies migrations from the Rails engine to the parent app.

Grateful for any help/suggestions you can offer. 

1. Thanks!