update-locked-requirements: Print some progress information.

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

tools/update-locked-requirements

@@ -11,6 +11,7 @@ compile_requirements () {
     output="$2"
     python_version="$3"
 
+    echo "Compiling $output"
     if [ "$python_version" == "py2" ]; then
         /srv/zulip-thumbor-venv/bin/pip-compile --quiet --allow-unsafe --no-header --output-file "$output" "$source"
     else