made account menu have min-width, changed max-width to rem from px (#2181)

src/components/dropdown/dropdown.scss

@@ -9,7 +9,8 @@
     border-radius: 0 0 5px 5px;
     background-color: $ui-blue;
     padding: 10px;
-    max-width: 260px;
+    min-width: 9rem;
+    max-width: 16.25rem;
     overflow: visible;
     color: $type-white;
     font-size: .8125rem;
@@ -88,8 +89,4 @@
             content: "";
         }
     }
-
-    @media only screen and (max-width: $tablet - 1) {
-        min-width: 160px;
-    }
 }