[Tests] fix nvm_list_aliases test to use mocks for LTS aliases

test/fast/Aliases/nvm_list_aliases works with LTS aliases

@@ -9,14 +9,20 @@ die () {
 
 set -e
 
+MOCKS_DIR="../Unit tests/mocks"
+
+# sample output at the time the test was written
+TAB_PATH="$MOCKS_DIR/nodejs.org-dist-index.tab"
+nvm_download() {
+  cat "$TAB_PATH"
+}
+
 nvm_alias_path() {
   nvm_echo "../../../alias"
 }
 
 nvm ls-remote >/dev/null || die 'nvm ls-remote (to populate LTS aliases) failed'
 
-MOCKS_DIR="../Unit tests/mocks"
-
 EXPECTED_OUTPUT="$(cat "$MOCKS_DIR/lts-star.txt")"
 STDOUT_OUTPUT="$(nvm_list_aliases "lts/*")"
 STDERR_OUTPUT="$(nvm_list_aliases "lts/*" 2>&1 >/dev/null)"