Standardize styling for hr elements and remove custom hr styling and classes that were no longer needed.

Fix styling on a few hr elements that looked wrong after global style was applied

templates/applications/new/step_2.html

@@ -20,7 +20,7 @@
     <p>
       {{ 'portfolios.applications.new.step_2_description' | translate }}
     </p>
-    <hr class="panel__break">
+    <hr>
     <application-environments inline-template v-bind:initial-data='{{ form.data|tojson }}'>
       <form method="POST" action="{{ url_for('applications.update_new_application_step_2', portfolio_id=portfolio.id, application_id=application.id) }}" v-on:submit="handleSubmit">
         <div class="subheading">{{ 'portfolios.applications.environments_heading' | translate }}</div>