Update release process to reflect current JIRA workflow

Author: jmikola

CONTRIBUTING.md

@@ -132,16 +132,17 @@ for more information.
 
 ### Transition JIRA issues and version
 
-Update the fix version field for all resolved issues with the corresponding ".x"
-fix version.
+All issues associated with the release version should be in the "Closed" state
+and have an appropriate resolution. Implemented issues should be resolved as
+"Fixed", while invalid issues may be "Duplicate", "Works as Designed", etc.
+
+Check the corresponding ".x" fix version to see if any of its resolved issues
+should be included in this release version.
 
 Update the version's release date and status from the
 [Manage Versions](https://jira.mongodb.org/plugins/servlet/project-config/PHPC/versions)
 page.
 
-Transition all resolved issues for this version to the closed state. If changing
-the issues in bulk, be sure to allow email notifications.
-
 ### Update version info
 
 The PHP driver uses [semantic versioning](http://semver.org/). Do not break