Update nebula repo to latest.

org.eclipse.ice.repository/category.xml

@@ -17,7 +17,7 @@
       </description>
    </category-def>
    <repository-reference location="http://download.eclipse.org/releases/oxygen/" enabled="true" />
-   <repository-reference location="http://download.eclipse.org/nebula/releases/1.3.0/" enabled="true" />
+   <repository-reference location="http://download.eclipse.org/nebula/releases/latest/" enabled="true" />
    <repository-reference location="http://download.eclipse.org/tools/orbit/downloads/drops/R20160520211859/repository" enabled="true" />
    <repository-reference location="http://download.eclipse.org/tools/orbit/downloads/drops/R20140525021250/repository" enabled="true" />
    <repository-reference location="http://download.eclipse.org/eavp/builds/next/" enabled="true" />

org.eclipse.ice.repository/pom.xml

@@ -77,7 +77,7 @@
 	                        <siteTemplateFolder>siteTemplateFolder/</siteTemplateFolder>
 							<associateSites>
 								<site>http://download.eclipse.org/eavp/builds/next/</site>
-								<site>http://download.eclipse.org/nebula/releases/1.3.0/</site>
+								<site>http://download.eclipse.org/nebula/releases/latest/</site>
 								<site>http://download.eclipse.org/tools/orbit/downloads/drops/R20160520211859/repository</site>
 								<site>http://download.eclipse.org/tools/orbit/downloads/drops/R20140525021250/repository</site>
 							</associateSites>

org.eclipse.ice.target.oxygen/oxygen.target

@@ -3,7 +3,7 @@
 <locations>
 <location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
 <unit id="org.eclipse.nebula.visualization.feature.feature.group" version="0.0.0"/>
-<repository location="http://download.eclipse.org/nebula/releases/1.3.0/"/>
+<repository location="http://download.eclipse.org/nebula/releases/latest/"/>
 </location>
 <location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
 <unit id="org.eclipse.remote.console.feature.group" version="0.0.0"/>