ISSUE_TEMPLATE.md in pact_broker-2.19.0

- old
+ new

@@ -1,4 +1,11 @@
+# Pre issue-raising checklist
+
+I have already (please mark the applicable with an `x`):
+
+* [ ] Upgraded to the latest Pact Broker OR
+* [ ] Checked the CHANGELOG to see if the issue I am about to raise has been fixed
+
 ## Software versions
 
 * **pact-broker gem version:** eg 2.3.1
 * **pact-broker docker version:** eg 2.3.1-1
 * **OS**: e.g. Mac OSX 10.11.5