Edits in training-guides/operator-editing-code

Fix wrong capitalization and add missing space.

Closes-Bug: #1284870
Change-Id: Ic52f34b8819b37320b61498ab0284fc6feaa49b7
Added sample file for Identity Service.

Added the policy.json file, and rearranged listing into sections.

Change-Id: Ied3775b122897b3815f62a86c01d1d2844f5f0fc
Partial-Bug: #1281348
Use nova network-create --bridge for FlatDHCP

Although it's not documented anywhere, the --bridge-interface option is
only used by the VLAN network manager, but this page explicitly
uses FlatDHCP, so the --bridge option is appropriate.

Change-Id: I2bb13ba53cdc09171f16862f6915687a07de2150
Merge "Added sample file for Identity Service."
Merge "Use nova network-create --bridge for FlatDHCP"
Merge "Edits in training-guides/operator-editing-code"