Add .$idx to nested section test.

js/test_cases/idx_and_len_nested/main.dust

@@ -6,11 +6,13 @@ Outside {?$len}$len is true{:else}$len is false{/$len}{~n}
 {#things}
     Inside Section $idx: {$idx}{~n}
     Inside Section $len: {$len}{~n}
+    Inside Section .$idx: {.$idx}{~n}
     Inside Section {?$idx}$idx is true{:else}$idx is false{/$idx}{~n}
     Inside Section {?$len}$len is true{:else}$len is false{/$len}{~n}
     {#.}
         Inside Nested Section $idx: {$idx}{~n}
         Inside Nested Section $len: {$len}{~n}
+        Inside Nested Section .$idx: {.$idx}{~n}
         Inside Nested Section {?$idx}$idx is true{:else}$idx is false{/$idx}{~n}
         Inside Nested Section {?$len}$len is true{:else}$len is false{/$len}{~n}
     {/.}