Change License to Apache-2.0

[aravindavk]

The license can be changed if all contributors to this library are in agreement. Please comment if the license change is Good.

@chawlanikhil24 @xiaohui @kshithijiyer @louisphilippereid @jnaulty @yocalebo @amarts

Included all the contributors mentioned here https://github.com/gluster/glustercli-python/graphs/contributors

[yocalebo]

I have no issues changing it to Apache-2.0

[kshithijiyer]

@aravindavk I have the following questions:

1. Why do we want to change it to Apache 2.0 now?
2. Glusterfs project is under GPLV2 and GPLV3?
3. What we be the advantages of this change?

[aravindavk]

Why do we want to change it to Apache 2.0 now?

Initially added those licenses since it was planned to deploy under glusterfs-python package itself. Now realized that we are not doing that and it is an external library and doesn't require dual licenses like major product GlusterFS.

Glusterfs project is under GPLV2 and GPLV3?

This library is not part of Glusterfs release, Can be independently installed. (With ssh support available, can be installed outside the Gluster Cluster too)

What we be the advantages of this change?

None.

[kshithijiyer]

As it is not a part of glusterfs project we can change the License. However we would need to add the boiler plate notice on all the files present in the repo(this looks like a bit of work).
Wouldn't it be better if we move it to only GPLv3 as it allows us to have code open sourced under different licenses.

@aravindavk I am good with Apache 2.0 but moving it to GPLv3 only would also be a good option.

[aravindavk]

One other reason for choosing Apache-2.0 is because it is a library and whoever using this library need not release the product in GPL.