Upgrade ember to canary to use query params

Following from #109, this upgrades to the latest canary build in order to enable queryParams, which hugely simplifies shipments pagination (and filtering, as we go). The guide is here: https://github.com/alexspeller/website/blob/query-params-guide/source/guides/routing/query-params.md

The canary builds are in vendor/assets/ember/; as soon as ember beta.3 is out we should try to specify that in the Gemfile for ember-source and remove those canary builds.

I haven't noticed any regressions so far. The pagination in Species+ was left intact, as that does not need to be done now (can use the old method for the time being).