Add cpanfile so github actions work

Author: petdance

cpanfile

@@ -0,0 +1,10 @@
+# Validate with cpanfile-dump
+# https://metacpan.org/release/Module-CPANfile
+
+on 'build' => sub {
+    requires 'ExtUtils::MakeMaker', '7.00';
+};
+
+on 'test' => sub {
+    requires 'Test::More', '0.94';  # So we can run subtests on v5.10
+};