Support query params for adding contribution

Just contributor ID, kind, and amount for now.

app/controllers/contributions/new.js

@@ -6,6 +6,8 @@ export default Controller.extend({
 
   kredits: service(),
 
+  queryParams: ['contributorId', 'kind', 'amount'],
+
   contributors: alias('kredits.contributors'),
   minedContributors: filterBy('contributors', 'id'),
 

app/router.js

@@ -20,7 +20,7 @@ Router.map(function() {
     this.route('new');
   });
   this.route('contributions', function() {
-    this.route('new');
+    this.route('new', { queryParams: ['contributorId', 'kind', 'amount'] });
     this.route('resubmit', { path: ':id/resubmit' });
   });
   this.route('contributors', function() {

app/routes/contributions/new.js

@@ -0,0 +1,9 @@
+import Route from '@ember/routing/route';
+
+export default Route.extend({
+
+  model (params) {
+    return { params };
+  }
+
+});

app/templates/contributions/new.hbs

@@ -6,7 +6,9 @@
     </header>
 
     <div class="content">
-      {{add-contribution contributors=sortedContributors save=(action "save")}}
+      {{add-contribution contributors=sortedContributors
+                         attributes=model.params
+                         save=(action "save")}}
     </div>
   </section>