Update Android dependencies

android/build.gradle

     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.1.3'
+        classpath 'com.android.tools.build:gradle:2.3.0'
     }
 }
 
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "23.0.1"
+    compileSdkVersion 26
+    buildToolsVersion "26.0.1"
 
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode 1
         versionName "1.0"
     }