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 
Just import const so it's obvious down below that you are referencing module members rather than local vars.
```python
import openstack_dashboard.dashboards.project.connections.reachability_tests.const as const