Added Message Spec

1. Added fixtures for message test
2. Added Message.friends_messages to list all messages from who the user follow
3. Added spec test to validate the friends_messages
Added messages controller spec

1. Added messages controller spec tests
2. Added list messages to list only the messages from who i follow
Added my_messages

1. Added my_messages method to list messages from a user
2. Updated the message list view, to show the user in each message
3. Added spec tests for my_messages and small refactor