Substituted deprecated {{each}} helper with recommended {{foreach}}

refs TryGhost/gscan#123

- As documentation says (https://docs.ghost.org/api/handlebars-themes/helpers/foreach/)  {{foreach}} should always be used instead of native {{each}} helper
- Deprecation warning was implemented in gscan and  will prompt when uploading the theme

error.hbs

@@ -42,16 +42,16 @@ You'll notice that we *don't* use any JavsScript, or ghost_head / ghost_foot in
                 <section class="error-stack">
                     <h3>Theme errors</h3>
                     <ul class="error-stack-list">
-                        {{#each errorDetails}}
+                        {{#foreach errorDetails}}
                             <li>
                                 <em class="error-stack-function">{{{rule}}}</em>
 
-                                {{#each failures}}
+                                {{#foreach failures}}
                                     <p><span class="error-stack-file">Ref: {{ref}}</span></p>
                                     <p><span class="error-stack-file">Message: {{message}}</span></p>
-                                {{/each}}
+                                {{/foreach}}
                             </li>
-                        {{/each}}
+                        {{/foreach}}
                     </ul>
                 </section>
                 {{/if}}