Rename fletch -> dartino

samples/github/android/GithubMock/app/build.gradle

 apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion 23
     buildToolsVersion "23.0.0"
 
     defaultConfig {
-        applicationId "com.google.fletch.githubmock"
+        applicationId "com.google.dartino.githubmock"
         minSdkVersion 22
         targetSdkVersion 23
         versionCode 1
         versionName "1.0"
     }
     buildTypes {
         release {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
 }
 
 dependencies {
     compile fileTree(include: ['*.jar'], dir: 'libs')
     compile 'com.android.support:support-v4:23.0.0'
 }