[openstack|compute] Add volume attachment methods
Updated gem spec to require json rather than multi_json; Fog::JSON will attempt to load and use multi_json first and then fallback to require json; removed hard coded references to multi_json
Merge branch 'master' of github.com:fog/fog into json_lib
Adding multi_json to GemFile as it is now an optional dependency for the gem
Added tests for Fog::JSON; Added Fog::JSON::LoadError class; Updated all MultiJson references to Fog::JSON
Merge branch 'master' of github.com:fog/fog into json_lib
[core] fixing brittle json test
[openstack|compute] Add volume method to server model
[openstack|compute] Add volume tests
Fix CHANGELOG fog version for digitalocean, xenserver and openstack
Merge pull request #1738 from rubiojr/changelog-fixes

Fix CHANGELOG fog version for digitalocean, xenserver and openstack
Merge pull request #1705 from frodenas/openstack_volumes

[openstack|compute] Add volume attachment methods
[vsphere|compute] fix incorrect filters.merge in networks model
Merge pull request #1742 from aussielunix/vsphere-bug-list-networks

[vsphere|compute] fix incorrect filters.merge in networks model
Merge pull request #1730 from rackspace/json_lib

[Core] Updated Fog::JSON to use JSON gem by default
add 2.0.0 to travis build list
Added pointers to provider specific documentation to README.md
Merge pull request #1744 from rackspace/provider_docs

Added pointers to provider specific documentation to README.md