Make venv-activate.sh compatible with sh and zsh
$  if [ "$0" == "$BASH_SOURCE" ]; then echo "a"; fi
sh: 1: [: sh: unexpected operator
@@ -51,7 +51,7 @@ function main() {
esac
done
- if [ "$0" == "$BASH_SOURCE" ] ; then
+ if [[ "$0" == "$BASH_SOURCE" ]] ; then
# Prevent running in script then exiting immediately
echo "ERROR: Invoke with 'source venv-activate.sh' or '. venv-activate.sh'"
else
