Adds MagnetoDB JSON client for tempest

Adds rest_client, http modules for magnetodb client.
Adds base class for rest api tests.

Partially implements: bp tempest-rest-api-tests
Change-Id: I37bd04efccc0829c51738f2f9cfa78c3d875d2c3
Add put_item API v1 method

Tests for controllers moved to
magnetodb/tests/unittests/api/openstack/v1/.

Change-Id: I04ccd5ceada67f7ffa6da1f7c6b435bf39ca7028
Implements: blueprint os-restful-api-put-item
Openstack API describe table

Implementation of 'describe_table' method of restful OpenStack API

Implements blueprint: os-restful-api-describe-table
Change-Id: I452488b3c9fe9aa8dfb021b4093e5793fbaa1765
Add OS API 'scan' method

OS API 'scan' method implemented

Implemented blueprint: os-restful-api-scan
Change-Id: Ia57bd5f59040ef31936abe4433fa200c2ecc3623
Get rid of empty secondary indexes in create_table

Remove local_secondary_indexes from response in case when
local_secondary_indexes were not in request.

Change-Id: I644b0e4832aa4466906747bd440b302bd47d68a7
Closes-Bug: #1288851
Add OS API 'query' method

OS RESTful API method 'query' implemented

Implements blueprint: os-restful-api-query
Change-Id: I9c3dde735ce777cd069e49bfee442c6593a9cd74
Merge "Get rid of empty secondary indexes in create_table"