[Tests] mock node in nvm_die_on_prefix test

test/fast/Unit tests/nvm_die_on_prefix

@@ -12,7 +12,7 @@ cleanup () {
   rm -rf "$TEST_DIR"
   alias nvm_has='\nvm_has'
   alias npm='\npm'
-  unset -f nvm_has npm
+  unset -f nvm_has npm node
 }
 
 die () {
@@ -61,6 +61,12 @@ npm() {
   fi
 }
 
+node() {
+  if [ "_$1" = "_-v" ]; then
+    echo "v0.0.0"
+  fi
+}
+
 OUTPUT="$(nvm_die_on_prefix 0 foo "$(nvm_version_dir new)" 2>&1)"
 [ -z "$OUTPUT" ] || die "'nvm_die_on_prefix' was not a noop when directory is equivalent; got '$OUTPUT'"