Pickers: Fix suggestions not having proper value selected (#4408)

* Revert "FocusTrapZone does not correctly trap focus when last child is FocusZone (#4172)"

This reverts commit 699fa69.

* fix picker suggestions and add many tests

* adding snap file

* adding change file

* improve test

* fix tests and config

* revert test changes

* last test update

* update test name and snapshot

* remove tests to expedite checkin

common/changes/office-ui-fabric-react/joschect-fix-pickers-suggestions_2018-03-29-23-30.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "office-ui-fabric-react",
+      "comment": "Pickers: fix bug where suggestions wouldn't have correct value selected",
+      "type": "patch"
+    }
+  ],
+  "packageName": "office-ui-fabric-react",
+  "email": "[email protected]"
+}

packages/office-ui-fabric-react/src/components/pickers/Suggestions/Suggestions.tsx

@@ -332,7 +332,7 @@ export class Suggestions<T> extends BaseComponent<ISuggestionsProps<T>, ISuggest
       >
         { suggestions.map((suggestion, index) =>
           <div
-            ref={ this._selectedElement }
+            ref={ suggestion.selected ? this._selectedElement : '' }
             // tslint:disable-next-line:no-string-literal
             key={ (suggestion.item as any)['key'] ? (suggestion.item as any)['key'] : index }
             id={ 'sug-' + index }