Reverts package name to master

Author: JoseAlcerreca

app/build.gradle

@@ -7,7 +7,7 @@ android {
     compileSdkVersion rootProject.compileSdkVersion
 
     defaultConfig {
-        applicationId "com.example.android.architecture.blueprints.reactive"
+        applicationId "com.example.android.architecture.blueprints.master"
         minSdkVersion rootProject.minSdkVersion
         targetSdkVersion rootProject.targetSdkVersion
         versionCode 1