update version to 4.2.0

Author: tibbi

app/build.gradle

@@ -10,8 +10,8 @@ android {
         applicationId "com.simplemobiletools.calendar"
         minSdkVersion 16
         targetSdkVersion 28
-        versionCode 127
-        versionName "4.1.3"
+        versionCode 128
+        versionName "4.2.0"
         multiDexEnabled true
         setProperty("archivesBaseName", "calendar")
     }