update left tabs for 8pt grid [#150271625]

Signed-off-by: Jonathan Berney <jberney@pivotal.io>

Author: reidmit

src/pivotal-ui/components/pui-variables.scss

@@ -670,7 +670,7 @@ $nav-tabs-title-font-size:                    16px;
 $tab-responsive-bg:                           $shadow-4;
 $tab-responsive-color:                        $text-color;
 $tab-responsive-active-color:                 $brand-5;
-$tab-responsive-radius:                       $border-radius-large;
+$tab-responsive-radius:                       $border-radius-base;
 $tab-responsive-pane-padding:                 10px;
 
 // Left tabs

src/pivotal-ui/components/tabs/tabs.scss

@@ -238,9 +238,9 @@ $tab-action-padding: ($base-unit/2) ($base-unit*2);
 
   .nav {
     a {
-      padding: 8px 10px;
+      padding: 8px;
       color: $tab-left-color;
-      margin: 5px 0;
+      margin: 4px 0;
       border-radius: $tab-left-radius;
       @include transition-pui();
     }