cpu_shares value can't be float.

[pingz]

if I use a float cpu_shares it will throw an exception as below:

c.create_container(image='some/image', cpu_shares=0.8)
Traceback (most recent call last):
File "", line 1, in
File "/usr/lib/python2.7/site-packages/docker/client.py", line 239, in create_container
return self.create_container_from_config(config, name)
File "/usr/lib/python2.7/site-packages/docker/client.py", line 247, in create_container_from_config
return self._result(res, True)
File "/usr/lib/python2.7/site-packages/docker/clientbase.py", line 106, in _result
self._raise_for_status(response)
File "/usr/lib/python2.7/site-packages/docker/clientbase.py", line 102, in _raise_for_status
raise errors.APIError(e, response, explanation=explanation)
docker.errors.APIError: 500 Server Error: Internal Server Error ("json: cannot unmarshal number 0.8 into Go value of type int64")

docker version:

Client version: 1.7.1
Client API version: 1.19
Package Version (client): docker-1.7.1-108.el7.centos.x86_64
Go version (client): go1.4.2
Git commit (client): 3043001/1.7.1
OS/Arch (client): linux/amd64
Server version: 1.7.1
Server API version: 1.19
Package Version (server): docker-1.7.1-108.el7.centos.x86_64
Go version (server): go1.4.2
Git commit (server): 3043001/1.7.1
OS/Arch (server): linux/amd64

docker-py:

docker.version
'1.4.0-dev'

I think it's something about the changes in the Docker API.