Verify Server Actions attributes of Nova APIs

Below listed Server Actions does not return response body. They only
return the response code.
This patch adds the JSON schema for the response code 202 & 204
and validate the Server Actions response code with added schema.

Server Action          Nova v2   Nova v3

addFixedIp            	202       202
addSecurityGroup        202       N/A
changePassword          202       204
confirmResize           204       202
createBackup            202       202
forceDelete             202       202
injectNetworkInfo       202       202
lock                    202       202
migrate                 202       202
os-migrateLive          202       202
os-resetState           202       202
os-start                202       202
os-stop                 202       202
pause                   202       202
reboot                  202       202
removeFixedIp           202       202
removeSecurityGroup     202       N/A
resetNetwork            202       202
resize                  202       202
restore                 202       202
resume                  202       202
revertResize            202       202
shelve                  202       202
shelveOffload           202       202
suspend                 202       202
unlock                  202       202
unpause                 202       202
unrescue                202       202
unshelve                202       202

Partially implements blueprint nova-api-attribute-test

Change-Id: Ie078186527e53c8990a6058056f908e61dc2da8a
Merge "Verify Server Actions attributes of Nova APIs"