Replaced client id with placeholder in sample application to make it clear that the user needs to specify their own client id.
Replaced client id with placeholder in sample application to make it clear that the user needs to specify their own client id.

AzureAD/azure-activedirectory-library-for-ruby,cosmincojocar/azure-activedirectory-library-for-ruby,cosmincojocar/azure-activedirectory-library-for-ruby,AzureAD/azure-activedirectory-library-for-ruby