Add test for the multi buildpack, courtesy of https://github.com/AlJohri

tests/apps/multi/app.py

@@ -0,0 +1,15 @@
+import os
+from flask import Flask, render_template
+from werkzeug.wsgi import SharedDataMiddleware
+
+app = Flask(__name__)
+
+@app.route('/')
+def hello_world():
+    return render_template('index.html')
+
+app.wsgi_app = SharedDataMiddleware(app.wsgi_app, { '/': os.path.join(os.path.dirname(__file__), 'static') })
+app.wsgi_app = SharedDataMiddleware(app.wsgi_app, { '/': os.path.join(os.path.dirname(__file__), 'static/.tmp') })
+
+if __name__ == '__main__':
+    app.run(host='0.0.0.0', debug=True)