Adding notes for ChainResolver fixes.

Fixes #1611

notes/0.13.7/maven-null-publish-date.md

@@ -0,0 +1,15 @@
+  [1618]: https://github.com/sbt/sbt/pull/1618
+  [1611]: Https://github.com/sbt/sbt/issues/1611
+  [@jsuereth]: https://github.com/jsuereth
+  
+  
+### Improvements
+
+* You can now publish to maven repositories that are `file` URLs.
+
+### Fixes 
+
+* When resolving from maven, and unable to read maven-metadata.xml file (common given the divergence in
+  Maven 3 and Ivy 2), we attempt to use LastModified timestamp in lieu of "published" timestamp.  
+  [#1618][1618] by [@jsuereth][@jsuereth]
+* NPE exception when using ChainResolver and maven repositories [#1611]/[1611] by [@jsuereth][@jsuereth]

sbt/src/sbt-test/dependency-management/publish-to-maven-local-file/build.sbt

@@ -22,6 +22,7 @@ lazy val analyze =
       organization := "com.example",
       version := "1.0.0-SNAPSHOT",
       resolvers += localRemote,
+      resolvers += Resolver.mavenLocal,
       resolvers += Resolver.sonatypeRepo("snapshots"),
       fullResolvers := fullResolvers.value.filterNot(_.name == "inter-project")
     )