Update EC2 related instance constants.
Update EC2 related instance constants.

andrewsomething/libcloud,mistio/libcloud,ByteInternet/libcloud,ByteInternet/libcloud,Kami/libcloud,Kami/libcloud,ByteInternet/libcloud,andrewsomething/libcloud,apache/libcloud,apache/libcloud,mistio/libcloud,apache/libcloud,andrewsomething/libcloud,mistio/libcloud,Kami/libcloud