Adds TODO

diff --git a/TODO.md b/TODO.md
new file mode 100644 (file)
index 0000000..19d1818
--- /dev/null
+++ b/TODO.md
@@ -0,0 +1,5 @@
+TODO
+====
+
+* Refactor to support multiple PHP versions (5.6, 7.0, 7.1, 7.2 etc) and multiple SAPIs at the same time?
+  One way to do that is to make `$series` as an array.