User can start a chat from detailed listing view

[brownmagik352]

• [x] add button to detailed listing view
• [x] make API call to start convo
• [x] show modal for first message?
• [x] how to actually send that first message?

[brownmagik352]

related to #65?

[brownmagik352]

Scenario: Start a chat about a listing and have it be visible by the correct people Given a listing exists from user "example1@email.com"

This will create a new listing with id 2 (first one is created in the given condition)

And I log in with email "example2@email.com" and password "password"
When I send a POST request to "/api/v1/conversations/start" with the following:
  """
    { "listing_id" : 2 }
  """
Then the response status should be "200"
And the response schema should match "conversation"
Given I log in with email "example1@email.com" and password "password"
When I send a GET request to "/api/v1/conversations/2"
Then the response status should be "200"
And the response schema should match "conversation"
Given I log in with email "example2@email.com" and password "password"
When I send a GET request to "/api/v1/conversations/2"
Then the response status should be "200"
And the response schema should match "conversation"
Given I log in with email "example3@email.com" and password "password"
When I send a GET request to "/api/v1/conversations/2"
Then the response status should be "403"

[brownmagik352]

having big problem with getting the channel to actually close