title: "realm migration needed", exception in android while retrieving values from realm db
body: <p>I am using Realm as a back end in my application. I have created one table named Setting. I added values in that table, by following the steps given on Realm's official site. 
  But when I am going to retrieve values from that table in, I getting exception</p>
  
  <blockquote>
    <p>"io.realm.exceptions.RealmMigrationNeededException: RealmMigration must be provided" on the line:" realm=Realm.getInstance(getApplicationContext());".</p>
  </blockquote>
  
  <p>Actually, I am new to android and Realm, so finding trouble to understand what is problem.</p>