Remove organization from the image field in the apb.yml

[cfchase]

Current behavior:
#apb.yml
image: ansibleplaybookbundle/my-apb
This means that the broker downloads the spec from an organization, but may actually download the image from an entirely different organization, leading to confusion.

Proposed:
#apb.yml
image: my-apb
ASB will assume the apb image is in the same repository and org where the spec was found.

Will require changes in:

• ansible-service-broker - no longer use the org in a spec and use where it's hosted instead.
• ansible-playbook-bundle - remove org from apb-init and build

Reasoning:

1. Stable - Allow a user to download an image, retag it, and then push it to a different org for either testing or production use without modifying and rebuilding. We want to test the built image as is without modifying it and introducing changes.
2. Less confusion - since a user may forget to change the org, they'd be testing the original image on a different org and may be confused why changes aren't reflected.
3. Reusable - we would want users and developers to be sharing images without forcing them to rebuild the image with changes before pushing to their own organization for use.

[jwmatthews]

https://trello.com/c/fIFsrFrf

[cfchase]

fusor/apb-examples#81
ansibleplaybookbundle/ansible-playbook-bundle#69