Tel - Create a conference call

== Scope of testing ==
    - Dialer app conference call functionality works
    - Integration between dialer and contacts app

== Test Steps ==
0. Pre-requisite:
    - Screen is unlocked,
    - addressbook-app and dialer-app are not already running
    - there are at least 4 valid contacts in the addressbook
1. Initiate a call with contact A
    > Verifiy that call is active
2. Once on live call screen, initiate another call to contact B by adding it to existing call.
    > Verify that Call with contact A is on hold and Active with Contact B
3. Merge the two calls to make a conference call
    > Verify that both calls with contact A & B are active.