CRUD Friends api endpoints

[brisag]

As a FE consumer, I need to consume Friends endpoints running on Heroku

Acceptance Criteria:
All endpoints are accessible using browser or postman

api_v1_user_friends GET /api/v1/users/:user_id/friends(.:format) api/v1/friends#index
POST /api/v1/users/:user_id/friends(.:format) api/v1/friends#create
api_v1_user_friend GET /api/v1/users/:user_id/friends/:id(.:format) api/v1/friends#show
PATCH /api/v1/users/:user_id/friends/:id(.:format) api/v1/friends#update
PUT /api/v1/users/:user_id/friends/:id(.:format) api/v1/friends#update
DELETE /api/v1/users/:user_id/friends/:id(.:format) api/v1/friends#destroy