writenig provider for sakuracloud ,wip

list ssh_keys and create disk

add models and requests for  create computer

create server at once

add bin and route file

update create_with

write getting_started wip. and create helper methods.

add sakura to mock_helper

add bin and route file

write getting_started wip. and create helper methods.

add mocks and test

create tests and write getting started

mv getting_started to docs
Merge branch 'pull_sakuracloud' of github.com:higanworks/fog into pull_sakuracloud
mv getting_started to docs