Install serialiser by default?

[backspace]

The _shouldSerializeHasMany override is good for saving child IDs in a parent, but it’s only enabled if someone chooses to install the ember-pouch serialiser. A new user encountered problems with this in #116. I see two solutions:

1. Add a generator to create the serialiser file and list it alongside the adapter in the README
2. Add the generator to the default blueprint so it’s installed with the addon

Maybe when the addon is installed, the adapter should also be created by default? Questions. Thoughts?

[mattmarcum]

this #124 fixes #1

right now the default blueprint doesn't run any generators - it just installs pouch/relational-pouch via bower: https://github.com/nolanlawson/ember-pouch/blob/master/blueprints/ember-pouch/index.js