added get_client(). added read_config(). renamed keys command group to key. added bucket command group. implemented command: storj-bucket list.
added get_client().
added read_config().
renamed keys command group to key.
added bucket command group.
implemented command: storj-bucket list.

Storj/storj-python-sdk,steenzout/python-storj,Miskerest/storj-python-sdk,frdwrd/storj-python-sdk