Update README.md to reflect current stemcell version
Update README.md to reflect current stemcell version

cloudfoundry/cf-mysql-release,CloudCredo/cf-mysql-release,krishna-mk/cf-mysql-release,kbastani/cf-mysql-release,cloudfoundry/cf-mysql-release,cloudfoundry/cf-mysql-release,krishna-mk/cf-mysql-release,cloudfoundry/cf-mysql-release,CloudCredo/cf-mysql-release,kbastani/cf-mysql-release,CloudCredo/cf-mysql-release,kbastani/cf-mysql-release,krishna-mk/cf-mysql-release