test: add basic tests for crystal and delegating lexers

spec/examples/jinja+python/funko.py.j2

@@ -0,0 +1,11 @@
+from flask import Flask, request
+
+app = Flask("{{name}}")
+
+@app.route('/')
+def handle():
+    return "Hello World from Flask!"
+
+@app.route('/ping')
+def ping():
+    return "OK"