Merge pull request #139 from WindowsAzure/dev

release 0.6.3
Update README.md
Update README.md
Update README.md
Rename Windows Azure to Microsoft Azure
Merge branch 'release-0.6.4' of https://github.com/WindowsAzure/azure-sdk-for-ruby into release-0.6.4
update version to 0.6.4
Merge pull request #142 from guangyang/release-0.6.4

Release 0.6.4