BVS-1981 test path integration with horizon

Reviewer: @kevinbenton  @kjiang 
CC @kyleforster  
tables are created in neutron db.
rest client is nsapp rest/rest_lib
all configuration is hardcoded at const.py 
Importing the module should be adequate to register the model classes
```
import openstack_dashboard.dashboards.project.connections.reachability_tests.reachability_test_db