drop the teams_users table
add the user_teams table to the database
create user_team associations for preparation of the state machine
Tests for the user_teams association
Add relationships for the user_teams in preparation of the state machine
test the model for association relationships
add the state_machine gem
Create the UserTeam model
Create the user_teams factory
delete unnecessary lines
fix typos
create the user_teams spec
Change a relationship for user and user_teams
add initial peding spec to new users
add unit test to verify user_team has an initial state of pending
modify the team model
Spec for the request method
add the request method
add an accepted condition for a team has_many users relationship
remove user belongs_to team relationship from the user model