Makes v3 API keypairs extension core

Adds os-keypairs to the core list for the V3 API.

Rename os-keypairs to keypairs as part of this change.

Fixes some incorrect urls in test_keypairs which still included
the tenant id

Updates api samples for servers since keypairs is now core and forms
part of the response by default

+DocImpact

Partially implements blueprint nova-v3-api

Change-Id: I8cdf52be0c8b19f7704848029a78373da8018cab
Fix compute_node_get_all() for Nova Baremetal

Change Ie5ef00c974b810336787e88c78c93c15ca2890d3 introduced
a regression leading to KeyError when a new baremetal node
is scheduled. This is due to the fact, that the mentioned
change assumes, that ComputeNode <--> Service is a 1-1
relationship, which is not true for Nova Baremetal driver.

This patch fixes the tables join in compute_node_get_all()
DB API method to work with 1-M relationship between ComputeNode
and Service models.

Closes-Bug: #1221620

Change-Id: I7c218d06f63cc2bf7d0e358f2f76366601179b0c
Removed duplicated class in exception.py

This commit 6f9ed562d5f6df1dc16029dcaffd4d2e6601099d had a mistake
which added two same classes ImageDownloadModuleMetaDataError to
exception.py, clear it now.

fixes bug 1223165
Change-Id: I2e7a30a63ab24d1ffb9f33a14db65c6fb3594cb0
Merge "Fix compute_node_get_all() for Nova Baremetal"
Update fedora dev env instructions

I just set up a new dev environment on Fedora.  Update the dev environment docs
to reflect the full list of packages I had to install.

Change-Id: Ifbdea54641094885fee08513f142593befcd465e
Merge "Makes v3 API keypairs extension core"
Merge "Update fedora dev env instructions"
Merge "Removed duplicated class in exception.py"