Top Nav shouldn't include giant bottom margin

In the 'default' and 'material' themes, we remove the default bootstrap
margin on the top navbar because it creates a gap between the sidenav
and the topnav. This should be a global style so that other themes can
take advantage of it. It looks best with a single 1px value on
alternate themes.

Change-Id: Ie0f3e5e22c29fe737d128af6d2fd6499fe9ee99a
Closes-Bug: #1518455

openstack_dashboard/static/dashboard/scss/components/_navbar.scss

@@ -12,3 +12,9 @@
     vertical-align: middle;
   }
 }
+
+.topbar {
+  .navbar {
+    margin-bottom: 1px;
+  }
+}

openstack_dashboard/themes/default/bootstrap/components/_navbar.scss

@@ -1,9 +1,9 @@
 .navbar {
-  margin-bottom: 0;
   border-top: none;
   border-right: none;
   border-left: none;
 
+  // Specificity Required
   .navbar-toggle {
     border-color: transparent;
   }
@@ -13,3 +13,10 @@
     margin-top: 2px;
   }
 }
+
+// Specificity required
+.topbar {
+  .navbar {
+    margin-bottom: 0;
+  }
+}

openstack_dashboard/themes/material/static/horizon/_styles.scss

@@ -30,10 +30,6 @@
   width: 100%;
   position: fixed;
   z-index: 4;
-
-  .navbar {
-    margin-bottom: 0;
-  }
 }