Update project SDK and API key

app/build.gradle

@@ -1,13 +1,13 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 22
-    buildToolsVersion "22.0.1"
+    compileSdkVersion 23
+    buildToolsVersion "23.0.1"
 
     defaultConfig {
         applicationId "org.traccar.manager"
         minSdkVersion 10
-        targetSdkVersion 22
+        targetSdkVersion 23
         versionCode 1
         versionName "1.0"
     }
@@ -19,6 +19,7 @@ android {
 }
 
 dependencies {
-    compile 'com.android.support:appcompat-v7:22.2.1'
-    compile 'com.google.android.gms:play-services:7.5.0'
+    compile 'com.android.support:appcompat-v7:23.1.0'
+    compile 'com.google.android.gms:play-services:8.4.0'
+    compile 'com.squareup.retrofit:retrofit:2.0.0-beta2'
 }