Added UnitTests project to MailKit.Net45.sln
Added UnitTests project to MailKit.Net45.sln

dsbenghe/MailKit,jstedfast/MailKit,sstraus/MailKit,eino-makitalo/MailKit,FubarDevelopment/MailKit,jamie-dainton/MailKit,rajeshwarn/MailKit,nachocove/MailKit,matt2003/MailKit,mganss/MailKit