Added an extra orderBy in getConversationsList (musonza#124)

* Added an extra orderBy in getConversationsList

Basically, this means: Order by `'mc_conversations.updated_at' desc` but whenever there are duplicated values for update_at then order those values by `'mc_conversations.id' desc.

update readme

Fixing StyleCI

Fixes for some empty spaces

Change order of dropping tables

php artisan migrate:refresh returns error due to mc_conversations foreign key.

Update README.md

Update README.md

specify foreign pivot key (musonza#112)

* specify foreign pivot key

if the user model is different from the default user model that time it generating the custom table id column but this is should always user_id

* Update Conversation.php

Update ConversationService.php (musonza#102)

Added $data array to 'start' method arguments.

Delete composer.lock

remove mockery dep