Error list Google GKE clusters - zones deprecated

## Summary

Container GKE Provider failed to list and do actions on Google Cloud because of the **zones** its now deprecated and now you should use **locations**

## Detailed Information

> Traceback (most recent call last):
File "container.py", line 39, in
gce.list_clusters()
File "container.py", line 33, in list_clusters
clusters = self.gke.list_clusters(ex_zone=zone)
File "/usr/local/lib/python2.7/site-packages/libcloud/container/drivers/gke.py", line 178, in list_clusters
response = self.connection.request(request, method='GET').object
File "/usr/local/lib/python2.7/site-packages/libcloud/container/drivers/gke.py", line 67, in request
response = super(GKEConnection, self).request(*args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/libcloud/common/google.py", line 813, in request
*args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/libcloud/common/base.py", line 638, in request
response = responseCls(**kwargs)
File "/usr/local/lib/python2.7/site-packages/libcloud/common/base.py", line 154, in __init__
self.object = self.parse_body()
File "/usr/local/lib/python2.7/site-packages/libcloud/common/google.py", line 277, in parse_body
raise ResourceNotFoundError(message, self.status, code)
libcloud.common.google.ResourceNotFoundError: u'\n\n \n \n Error 404 (Not Found)!!1\n \n *{margin:0;padding:0}html,code{font:15px/22px arial,sans-serif}html{background:#fff;color:#222;padding:15px}body{margin:7% auto 0;max-width:390px;min-height:180px;padding:30px 0 15px}* > body{background:url(//www.google.com/images/errors/robot.png) 100% 5px no-repeat;padding-right:205px}p{margin:11px 0 22px;overflow:hidden}ins{color:#777;text-decoration:none}a img{border:0}@media screen and (max-width:772px){body{background:none;margin-top:0;max-width:none;padding-right:0}}#logo{background:url(//www.google.com/images/branding/googlelogo/1x/googlelogo_color_150x54dp.png) no-repeat;margin-left:-5px}@media only screen and (min-resolution:192dpi){#logo{background:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) no-repeat 0% 0%/100% 100%;-moz-border-image:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) 0}}@media only screen and (-webkit-min-device-pixel-ratio:2){#logo{background:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) no-repeat;-webkit-background-size:100% 100%}}#logo{display:inline-block;height:54px;width:150px}\n \n \n

404. That\u2019s an error.\n

The requested URL /v1/projects//zones/clusters was not found on this server. That\u2019s all we know.'

Start by reading libcloud/container/drivers/gke.py, especially list_clusters and the request path shown in the traceback. Reproduce the container.py list_clusters call against Google GKE and verify that cluster listing and related actions use locations rather than the deprecated zones endpoint without returning a 404.

Written by the indexing model from the issue text.