Update libraries, add proguard filters to be under 64K limit

build.gradle

@@ -7,7 +7,7 @@ buildscript {
 
     dependencies {
         // NOTE: Always use fixed version codes not dynamic ones, e.g. 0.7.3 instead of 0.7.+, see README for more information
-        classpath 'com.android.tools.build:gradle:2.0.0'
+        classpath 'com.android.tools.build:gradle:2.1.0'
         classpath files('gradle-witness.jar')
         // bintray dependency to satisfy dependency of openpgp-api lib
         classpath 'com.novoda:bintray-release:0.2.7'
@@ -49,5 +49,5 @@ project(':extern:bouncycastle') {
 // See http://tools.android.com/tech-docs/new-build-system/tips#TOC-Controlling-Android-properties-of-all-your-modules-from-the-main-project.
 ext {
     compileSdkVersion = 23
-    buildToolsVersion = '23.0.1'
+    buildToolsVersion = '23.0.2'
 }