Update build to Tycho 0.23.1

Most important change in Tycho: "JDT/APT, Equinox and p2 bundles shipped
with Tycho have been updated from Mars RC2a to Mars final."

https://wiki.eclipse.org/Tycho/Release_Notes/0.23#Milestone_0.23.1

Change-Id: I1d3bd78b5536df52cb34ea182364a72a78761513
Signed-off-by: Markus Knauer <mknauer@eclipsesource.com>
diff --git a/releng/org.eclipse.epp.config/parent/pom.xml b/releng/org.eclipse.epp.config/parent/pom.xml
index 98e9e76..94b39ea 100644
--- a/releng/org.eclipse.epp.config/parent/pom.xml
+++ b/releng/org.eclipse.epp.config/parent/pom.xml
@@ -24,7 +24,7 @@
   <properties>
     <java.version>1.7</java.version>
     <maven.version>3.1.1</maven.version>
-    <tycho.version>0.23.0</tycho.version>
+    <tycho.version>0.23.1</tycho.version>
     <tycho.extras.version>${tycho.version}</tycho.extras.version>
     <tycho.scmUrl>scm:git:git://git.eclipse.org/gitroot/epp/org.eclipse.epp.packages.git</tycho.scmUrl>
     <cbi.version>1.1.2</cbi.version>