Update CHANGELOG file

Author: ljackiewicz

CHANGELOG.md

@@ -1,12 +1,46 @@
 ChangeLog
 
-1.5.15 - 1.5.19
+1.5.21
 =====================
-**TODO**
+* #1099: Fix inability to trigger a build of merge commit on merged Merge Request
 
-1.5.14
+1.5.20
+=====================
+* #1111: Add possibility to delete the source branch after succeed merge
+* #1118: Fix an error blocking Multibranch Pipeline projects from being triggered
+
+1.5.19
+=====================
+* Fix broken javadoc
+
+1.5.18
+=====================
+* #1032: Set commit status to 'canceled' only when user aborts build from UI
+* #1063: Better compatibility with Configuration as Code plugin
+
+1.5.17
+=====================
+* #998: Add possibility to trigger builds only when new commits were pushed to Merge Request (prevents to trigger builds for non-code changes in Merge Requests)
+
+1.5.16
 =====================
 * #866: Better compatibility with Configuration as Code plugin (useAuthenticatedEndpoint)
+* #903: Add possibility to force build with added MR label(s)
+* #916 and #1017: Allow for project/folder level GitLab Token API credentials to be used for GitLab connection
+* #951: Fix inability to trigger builds on accepted Merge Request
+* #1002: Fix that the plugin checks only global permissions instead of both global and project-level permissions
+* #1008: Fix NPE during commit status retrieval by gitlabCommitStatus step
+* #1012: Fix NPE if SCM revision is null (probably occurs only while using with Gitlab Branch Source Plugin)
+* #1014: Fix another NPE while using this plugin with Gitlab Branch Source Plugin
+
+1.5.15
+=====================
+* #991: Add documentation for addGitLabMRComment step
+
+1.5.14
+=====================
+* #969: Add gitlabUserUsername variable
+* #977: Add possibility to handle push event with branch deletion
 
 1.5.13
 =====================