OpenNebula

As reported in https://github.com/OpenNebula/docs/issues/30

Please add license and copyright statement to `README.md`.
Assuming the same license as OpenNebula it would be something like

Copyright 2002-2015 OpenNebula Project (OpenNebula.org), C12G Labs

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.

It might be a good idea to commit the full text of the license as well.

Thank you.