Make client deal with expired token transparently.

- Use OwnerPassword resource instead of implicit to match how it is done is cf
- Check if the token is about to expire and use refresh token if so.
- Remove unneeded unit tests
Fix to avoid adding null service names to list of bound application
services.
Merge pull request #60 from nierajsingh/master

Fixed bug where null service name is added to app services
Bump to cloudfoundry-client-lib to 0.8.6
Bump cloudfoundry-client-lib to next snapshot