Upgrade Tycho to 1.3

With the upcoming Eclipse release 2018-12 a new version of Tycho has
been released. Upgrade the Tycho related build steps to the new version
in the Maven build.

Change-Id: Ifff186a9f97ed9faf70f15b20396724b0c9e801c
Signed-off-by: Michael Keppler <Michael.Keppler@gmx.de>

org.eclipse.jgit.packaging/pom.xml

@@ -59,7 +59,7 @@
   <name>JGit Tycho Parent</name>
 
   <properties>
-    <tycho-version>1.2.0</tycho-version>
+    <tycho-version>1.3.0</tycho-version>
     <tycho-extras-version>${tycho-version}</tycho-extras-version>
     <target-platform>jgit-4.6</target-platform>
   </properties>

pom.xml

@@ -200,7 +200,7 @@
     <slf4j-version>1.7.2</slf4j-version>
     <log4j-version>1.2.15</log4j-version>
     <maven-javadoc-plugin-version>3.0.1</maven-javadoc-plugin-version>
-    <tycho-extras-version>1.2.0</tycho-extras-version>
+    <tycho-extras-version>1.3.0</tycho-extras-version>
     <gson-version>2.8.2</gson-version>
     <spotbugs-maven-plugin-version>3.1.9</spotbugs-maven-plugin-version>
     <maven-surefire-version>2.22.1</maven-surefire-version>