No longer necessary to import Bootstrap dropdown styles in index

src/shared/styles/index.scss

@@ -18,7 +18,6 @@
     @import "bootstrap/scss/images";
     @import "bootstrap/scss/grid";
     @import "bootstrap/scss/transitions";
-    @import "bootstrap/scss/dropdown";
     @import "bootstrap/scss/nav";
     @import "bootstrap/scss/alert";
     @import "bootstrap/scss/media";