Create virtual environment in hidden folder.

This is the more common approach, to name
the folder .venv and not clutter the root
directory.

dali_mon

@@ -1,6 +1,6 @@
 #!/bin/bash
-[ -f venv/bin/activate ] || python3 -m venv venv
-source ./venv/bin/activate
+[ -f .venv/bin/activate ] || python3 -m venv .venv
+source ./.venv/bin/activate
 python3 -m pip install --upgrade pip > /dev/null
 python3 -m pip install -r requirements.txt > /dev/null
 python3 -OO source/dali_mon.py $*