Added font-family to textarea. This change solves the tiny-font problem in forms.

Author: Bruno Bonamin

app/assets/stylesheets/active_admin/_forms.css.scss

@@ -79,6 +79,7 @@ form {
     border: 1px solid #c9d0d6;
     @include rounded;
     font-size: 0.95em;
+    font-family: Helvetica, Arial, sans-serif;
     outline: none;
     padding: 8px $text-input-horizontal-padding 7px;