Updated to SDK version 22 (Android 5.1)

app/build.gradle

 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 21
-    buildToolsVersion "21.1.2"
+    compileSdkVersion 22
+    buildToolsVersion "22.0.0"
 
     defaultConfig {
         applicationId "com.xabber.androiddev"
         minSdkVersion 14
-        targetSdkVersion 21
+        targetSdkVersion 22
         versionCode 136
         versionName '0.10.36'
     }
 
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
-        }
-    }
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_7
         targetCompatibility JavaVersion.VERSION_1_7
@@ -25,7 +19,7 @@ android {
 }
 
 dependencies {
-    compile 'com.android.support:appcompat-v7:21.0.3'
-    compile 'com.android.support:support-v13:21.0.3'
+    compile 'com.android.support:appcompat-v7:22.0.0'
+    compile 'com.android.support:support-v13:22.0.0'
     compile project('otr4j')
 }