deposit: conferences typeahead requirejs impr.

Some fixes of conferences typeahead regarding requirejs. It was working anyway, but now it works better ;)

depends on: https://github.com/inveniosoftware/invenio/pull/2277
Why do you need the variable Bloodhound if it is not used afterwards?

For the moment we don't have Bloodhound export on the INSPIRE settings https://github.com/inspirehep/inspire-next/blob/master/inspire/base/static/js/settings.js#L48

And the current file looks like https://github.com/inspirehep/inspire-next/blob/master/inspire/modules/deposit/static/js/deposit/conferences_typeahead.js#L25 which works.

I guess Bloodhound export is needed to make this file work?https://github.com/inveniosoftware/invenio/blob/be1925bce9658bcc30c41d5f98e41d7db9e6ff8e/invenio/modules/search/static/js/search/typeahead.js it is not enough with adding the ```typeahead.bundle.js```?