Dasherize All The things

This version includes a new command which normalizes how you reference
models in belongsTo and hasMany relationships to their dasherized
from. Looking up via camelCase, variable, or App.Post will be removed
for Ember Data 1.0,

Running ember watson:convert-ember-data-model-lookups will transform
models looking like the following:

export default DS.Model.extend({
  postComments: DS.hasMany('postComment', {async: true})
});

To:

export default DS.Model.extend({
  postComments: DS.hasMany('post-comment', {async: true})
});

Big thanks to Stanley Stuart for his
work on this command.