Added hint to update the library

Change-Id: I131b5aed3c1e7d443fbb7452fd1a7e0ced1edfe8
diff --git a/Changes b/Changes
index 4dff93c..cd25cd4 100644
--- a/Changes
+++ b/Changes
@@ -2,8 +2,9 @@
     - [bugfix] Security upgrade of Jackson for CVE-2017-17485 and
       CVE-2018-7489 (diewald)
 
-0.30 2018-07-31
-    - Introduced docGroupRef and added VC reference in collection query (margaretha)
+0.30 2018-10-09
+    - Introduced docGroupRef and added VC reference in collection query
+      (margaretha)
     - Fixed checking error in QuerySerializer (margaretha)
 
 0.29 2018-07-23
@@ -12,6 +13,7 @@
     (fixes #42; diewald)
     - Fix support for verbatim string values in collection queries
     (diewald)
+    - Added hint to update the library (diewald)
 
 0.28 2018-01-10
     - Added some enums for koral:operation (margaretha)
diff --git a/README.md b/README.md
index ccc1dd2..e62aafc 100644
--- a/README.md
+++ b/README.md
@@ -101,6 +101,14 @@
 
     mvn install -Dhttps.protocols=TLSv1.2
 
+To update an existing installation, pull the latest version at ```[install-dir]``` 
+
+```
+$ git pull origin master
+```
+
+Afterwards, rerun the test suite and package or install the library.
+
 ## Prerequisites
 
 * Java 8 (OpenJDK or Oracle JDK with JCE)