MH-13638, Update NPM

This patch updates node and npm to the latest LTS version which [should
hopefully fix the package-lock.json problem](npm/cli#76 (comment))
although this is hard to verify.

Worst case, we just upgraded npm.

Author: lkiesow

modules/admin-ui/package-lock.json

@@ -39,8 +39,8 @@
     <json-simple.version>1.1.1</json-simple.version>
     <karaf.version>4.2.2</karaf.version>
     <mina.version>2.1.0</mina.version>
-    <node.version>v10.15.1</node.version>
-    <npm.version>6.4.1</npm.version>
+    <node.version>v10.16.0</node.version>
+    <npm.version>6.9.0</npm.version>
     <osgi.compendium.version>5.0.0</osgi.compendium.version>
     <osgi.core.version>5.0.0</osgi.core.version>
     <osgi.enterprise.version>5.0.0</osgi.enterprise.version>