This patch adds "router create" command to osc using sdk.
NOTE: Test for --project needs support for fake identity client v2 and v3.
These tests will be added in other patches.
NOTE: external_gateway_info and routes are not supported to be passed to
create command now. They will be supported in another tow patches.
NOTE: Creating a ha router is not supported for now. Will support it in
another patch.
Change-Id: I7642295d27c27dd498331ae1da1c293706d8f6af
Implements: blueprint neutron-client
Partial-bug: #1519503
6158ebb0e0