Adds threads table. has many messages
Adds messages#show view and controller methods
Inbox: Shows all messages for a certain user
Edits @user to be more DRY in session#create
Changes routing to homepage. if logged in, root is user homepage
  * otherwise, shows info page
Changes to models and associations after adding Threads model
Edits path of homepage icon & log out link in nav bar
Renders navbar partial in layout
Creates seed data for easier testing
Wraps Facebook and LinkedIn in p tags, adds "Sign up w/Email" link
Adds view for business#new
Adds view for message#create
Separates user id into business_owner/customer_id's in messages table
Changes routing for home page depending on logged in status