Scenario 1 addition (split connection string and fix unit tests)

I've fixed the tests and removed the connection string. The updated parameters for testing are:

The Media Services unit tests use the following environment variables:
AZURE_MEDIA_SERVICES_ACCOUNT_NAME - account name for connection to media services. Required.
AZURE_MEDIA_SERVICES_ACCESS_KEY - access key for connection to media services. Required.
AZURE_MEDIA_SERVICES_ENDPOINT_URI - media services endpoint URI. Optional. Default value is https://media.windows.net/API
AZURE_MEDIA_SERVICES_OAUTH_ENDPOINT_URI - OAuth endpoint URI. Optional. Default value is https://wamsprodglobal001acs.accesscontrol.windows.net/v2/OAuth2-13