java: Release 2.1.5

This has already been uploaded to bintray and maven.

Notable changes:
- JNI reference errors are gone
- sync watcher doesn't poll any more

The TODOs app works with the latest changes, though there is still
some bluetooth-related flakiness.

Change-Id: I77c0c036c2ef8bbddbe52efe95c57454614b7581
diff --git a/android-lib/build.gradle b/android-lib/build.gradle
index bd470bd..0330a08 100644
--- a/android-lib/build.gradle
+++ b/android-lib/build.gradle
@@ -30,7 +30,7 @@
 
 // You should change this after releasing a new version of the library. See the
 // list of published versions at https://repo1.maven.org/maven2/io/v/vanadium-android.
-def releaseVersion = '2.1.4'
+def releaseVersion = '2.1.5'
 
 android {
     buildToolsVersion '23.0.1'
diff --git a/lib/build.gradle b/lib/build.gradle
index ac6b4f4..1a27b83 100644
--- a/lib/build.gradle
+++ b/lib/build.gradle
@@ -23,7 +23,7 @@
 
 // You should change this after releasing a new version of the library. See the
 // list of published versions at https://repo1.maven.org/maven2/io/v/vanadium.
-def releaseVersion = '2.1.4'
+def releaseVersion = '2.1.5'
 
 dependencies {
     compile group: 'joda-time', name: 'joda-time', version: '2.7'