Update gradle, .gitignore, add art screen and update readme

.gitignore

@@ -6,6 +6,7 @@
 # Built application files
 *.apk
 *.ap_
+app/free_google/*
 
 # Files for the ART/Dalvik VM
 *.dex
@@ -39,7 +40,6 @@ captures/
 
 # Intellij
 *.iml
-<<<<<<< HEAD
 .idea/workspace.xml
 .idea/tasks.xml
 .idea/gradle.xml
@@ -49,19 +49,16 @@ captures/
 # Keystore files
 # Uncomment the following line if you do not want to check your keystore files in.
 #*.jks
-=======
 .idea/*
 
 # Keystore files
 *.jks
->>>>>>> master
 
 # External native build folder generated in Android Studio 2.2 and later
 .externalNativeBuild
 
 # Google Services (e.g. APIs or Firebase)
 google-services.json
-<<<<<<< HEAD
 
 # Freeline
 freeline.py
@@ -70,5 +67,11 @@ freeline_project_description.json
 
 # Iml Files
 app/app.iml
-=======
->>>>>>> master
+
+# Art
+art/screen*.png
+art/logo_512.png
+
+# Dir linux
+.directory
+*/.directory