camelize module names
camelize module names

This doesn't break any tests, although [this
discussion](https://github.com/samselikoff/ember-cli-mirage/pull/354#issuecomment-153162997)
suggests it is probably a breaking change.

This change is necessary to load fixtures for dash-containing model names.

lazybensch/ember-cli-mirage,jherdman/ember-cli-mirage,lependu/ember-cli-mirage,HeroicEric/ember-cli-mirage,samselikoff/ember-cli-mirage,alvinvogelzang/ember-cli-mirage,blimmer/ember-cli-mirage,samselikoff/ember-cli-mirage,alecho/ember-cli-mirage,unchartedcode/ember-cli-mirage,lazybensch/ember-cli-mirage,cs3b/ember-cli-mirage,unchartedcode/ember-cli-mirage,alvinvogelzang/ember-cli-mirage,alecho/ember-cli-mirage,unchartedcode/ember-cli-mirage,samselikoff/ember-cli-mirage,jherdman/ember-cli-mirage,mixonic/ember-cli-mirage,HeroicEric/ember-cli-mirage,makepanic/ember-cli-mirage,lependu/ember-cli-mirage,unchartedcode/ember-cli-mirage,blimmer/ember-cli-mirage,mixonic/ember-cli-mirage,ballPointPenguin/ember-cli-mirage,escobera/ember-cli-mirage,escobera/ember-cli-mirage,makepanic/ember-cli-mirage,samselikoff/ember-cli-mirage,jherdman/ember-cli-mirage,jherdman/ember-cli-mirage,ballPointPenguin/ember-cli-mirage,cibernox/ember-cli-mirage,cibernox/ember-cli-mirage,cs3b/ember-cli-mirage