Added warning in the pull request template that this is a read only repo (#91)

Nyholm · web-flow · commit 8f21c9802388 · 2016-08-31T05:53:32.000+02:00
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
@@ -0,0 +1,5 @@
+This is a READ ONLY repository. 
+
+Please make your pull request to https://github.com/php-cache/cache
+
+Thank you for contributing. 
