klein: Update requirements

frameworks/Python/klein/requirements.txt

@@ -1,5 +1,4 @@
-klein==15.0.0
-
-mysqlclient==1.3.6
-SQLAlchemy==1.0.4
-jinja2==2.7.3
+klein==15.3.1
+mysqlclient==1.3.7
+SQLAlchemy==1.0.12
+jinja2==2.8