Add attribute firewall_policy to nic
Add ready? to server class
Mark servers collection tests as pending
Fix Joyent service declarations

When the Joyent provider was merged in it was after a reworking of how
requires and services were declared.

This meant the call to `service` was no longer correct.

This updates the signature and the mocked tests now pass (locally at
least) however the structuring and placement of the files may not be
inconsistent with the results of [GH-1712]
Merge pull request #2662 from fog/fix_joyent_service_declarations

Fix Joyent service declarations
Changes to rely on fog-core

This references `fog-core` and removes the files it now contains.
[google|compute] reraise LoadError when google-api-client missing
Merge pull request #2659 from dJason/patch-1

[cloudsigma] adding firewall_policy attribute and ready? method for servers
Merge pull request #2663 from fog/use_fog_core

Changes to rely on fog-core
add fog-core to 1.8.7 Gemfile also