Removed gulp-ember-handlebars from the list

Hi,

I've read all that's been said [here](https://github.com/fuseelements/gulp-ember-handlebars/issues/2), in the `gulp-ember-handlebars` repo and also elsewhere, and I do think that blacklisting this plugin by just stating that it's a "duplicate of gulp-handlebars" isn't really telling the whole picture.

At the moment, there is really no alternative (at least that I know of) for those of us who use gulp to precompile Ember Handlebars templates. I do therefore feel that blacklisting it is a bit unwarranted.

Yes, in the future, it might be that we don't really need this plugin if gulp-handlebars is extended to support a custom compiler (to use e.g. `ember-template-compiler`) but until that has happened, please don't blacklist a module that is really useful to some of us.