Revert "Allow executing run script w/o prior setup"

This reverts commit 7f91de7399.

Fixes #540

run

@@ -7,19 +7,6 @@ set -euo pipefail
 
 SCRIPT_DIR="$(builtin cd "$(dirname "${BASH_SOURCE[0]}")" && pwd -P)"
 
-if [[ ! -x "$(command -v python3)" ]]; then
-    echo "Python3 required -- please install first"
-    exit 1
-fi
-
-if [[ ! -d "$SCRIPT_DIR/venv" ]]; then
-    python3 -m venv venv
-    "$SCRIPT_DIR"/venv/bin/pip install --upgrade pip
-    "$SCRIPT_DIR"/venv/bin/pip install -r requirements.txt
-fi
-
-cd "$SCRIPT_DIR"
-
 # Set directory to serve static content from
 SUBDIR="${1:-app}"
 export APP_ROOT="$SCRIPT_DIR/$SUBDIR"
@@ -37,7 +24,7 @@ if [[ "$SUBDIR" == "test" ]]; then
     pytest -sv
 else
     mkdir -p "$STATIC_FOLDER"
-    "$SCRIPT_DIR"/venv/bin/python -um app \
+    python3 -um app \
       --host "${ADDRESS:-0.0.0.0}" \
       --port "${PORT:-"${EXPOSE_PORT:-5000}"}"
 fi