Merge #1371

1371: Fix relevance sorting on search r=ashleygwilliams

To sort by relevence, the backend expects the sort string to either be
not present, or set to the value "relevance". Right now the backend is
either sending the string `null` or an empty string. Neither of these do
what we want.

Fixes #1370

Author: bors-voyager[bot]

app/controllers/search.js

@@ -13,7 +13,6 @@ export default Controller.extend(PaginationMixin, {
     q: alias('search.q'),
     page: '1',
     per_page: 10,
-    sort: null,
 
     model: readOnly('dataTask.lastSuccessful.value'),
 

app/templates/search.hbs

@@ -38,7 +38,7 @@
 
                 {{#rl-dropdown tagName="ul" class="dropdown" closeOnChildClick="a:link"}}
                     <li>
-                        {{#link-to (query-params page=1 sort="")}}
+                        {{#link-to (query-params page=1 sort="relevance")}}
                             Relevance
                         {{/link-to}}
                     </li>