Update runtime.txt

Apparently heroku updated their python, so lets update that here too
DelightReza · Mar 14, 2018 · c7a6994 · c7a6994
1 parent 7384776
commit c7a6994
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/runtime.txt b/runtime.txt
@@ -1 +1 @@
-python-3.6.3
+python-3.6.4