Make sure the new versions directory is filtered out of nvm_ls output (in zsh).

test/fast/Listing versions/Running "nvm ls" should filter out "versions"

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+mkdir ../../../v0.1.3
+mkdir ../../../v0.2.3
+
+. ../../../nvm.sh
+
+mkdir ../../../versions
+
+[ -z "$(nvm ls | \grep 'versions')" ]
+# The result should contain only the appropriate version numbers.
+
+rmdir ../../../versions
+