Added Google Play store graphics and screnshots.

Added artifacts.gradle

artifacts.gradle

@@ -0,0 +1,26 @@
+android.applicationVariants.all { variant ->
+    def appName
+
+    //Check if an applicationName property is supplied; if not use the name of the parent project.
+    if (project.hasProperty("applicationName")) {
+        appName = applicationName
+    } else {
+        appName = parent.name
+
+    }
+
+    variant.outputs.each { output ->
+        def newApkName
+        def baseName = (output.baseName.equalsIgnoreCase("release") ? '' : "-${output.baseName}" )
+
+        //If there's no ZipAlign task it means that our artifact will be unaligned and we need to mark it as such.
+        if (output.zipAlign) {
+            newApkName = "${appName}-${variant.versionName}${baseName}.apk"
+
+        } else {
+            newApkName = "${appName}-${variant.versionName}${baseName}-unaligned.apk"
+
+        }
+        output.outputFile = new File(output.outputFile.parent, newApkName)
+    }
+}