Updates the license file to have the correct date range: 2016-2017
Updates the license file to have the correct date range: 2016-2017

sendgrid/sendgrid-csharp,sendgrid/sendgrid-csharp,dubrovkinmaxim/sendgrid-csharp,sendgrid/sendgrid-csharp,dubrovkinmaxim/sendgrid-csharp