Remove unnecessary styles in top bar

Not sure why these properties were added, but they no longer seem to be
necessary.

app/assets/stylesheets/layout/account_menu.scss

@@ -21,7 +21,6 @@
 
   .is-submenu-item {
     display: block;
-    height: auto;
     margin-bottom: 0;
   }
 

app/assets/stylesheets/layout/admin_header.scss

@@ -15,7 +15,6 @@
   }
 
   .top-bar {
-    height: auto;
     padding-top: $line-height / 2;
 
     @include breakpoint(small only) {
@@ -25,10 +24,6 @@
         padding-bottom: 0;
         margin-bottom: 0;
 
-        .submenu {
-          position: initial;
-        }
-
         a {
           font-weight: normal;
         }
@@ -70,11 +65,4 @@
       }
     }
   }
-
-  .top-bar .menu > li {
-
-    @include breakpoint(medium) {
-      height: auto !important;
-    }
-  }
 }