As an app developer I want the service binding to be available to the app via the VCAP_SERVICES env var

[danail-branekov]

GIVEN I have bound an app to a managed service
WHEN I check the $VCAP_SERVICES env var from within the app
THEN I see an entry representing the binding

Dev notes:

• In order to make use of the already existing vcap_services builder,
  • the binding credentials object should be marshalled under the credentials key of an opaque secret
  • the name of the secret above should be set to the CFServiceBinding.Status.Credentials.Name
• VCAP_SERVICES docs
• Managed services proposal