Update .circleci/config.yml

Author: snyuryev

.circleci/config.yml

@@ -1,22 +1,17 @@
-version: 2
+# For a detailed guide to building and testing on iOS, read the docs:
+# https://circleci.com/docs/2.0/testing-ios/
+
+version: 2.1
+
 jobs:
   build:    
     docker:
       - image: cirrusci/flutter:latest
-
-    branches:
-      only: master
-
     steps:
       - checkout
-
       - run:
           name: Run Flutter doctor
           command: flutter doctor
-          
       - run:
           name: Build the Android version
-          command: flutter build apk 
-
-      #- store_artifacts:
-      #    path: build/app/outputs/apk/release/app-release.apk
+          command: flutter build apk