API Server

GET   /api/v0/token  send username/password, get auth token
POST  /api/v0/users  Creates a new user with username/password
GET   /api/v0/users/<username>  Retrieves the user with username <username>
GET   /api/v0/resource  Retrieves example resource, requires authentication

Authorization flow:
1. Create a user by posting to /api/v0/users with username and password in JSON format
2. Get a token by sending username/password using HTTP Basic authorization to /api/v0/token
3. Cache token on client and send token in username field (Basic auth) on GET requests to resource
4. Token default expiration is 10 minutes; when request fails due to auth, get another token

# Examples
# Register a user
$ curl -i -X POST -H "Content-Type: application/json" -d '{"username":"test_user","password":"test_password"}' http://127.0.0.1:5000/api/v0/users

# Get a resource with username/password
$ curl -u test_user:test_password -i -X GET http://127.0.0.1:5000/api/v0/resource

# Get an auth token
$ curl -u test_user:test_password -i -X GET http://127.0.0.1:5000/api/v0/token

# Get resource using retrieved token, token value is sent in username field, password is unused so can be anything
$ curl -u token_value:unused -i -X GET http://127.0.0.1:5000/api/v0/resources

Run the tests:
$ nosetests

to run a single test controller:
nosetests app.tests.test_filename:TestControllerClassName

to run a single test method:
nosetests app_name.tests.test_filename:TestControllerClassName.test_method_name
(e.g.: nosetests api.tests.test_users:UsersTest.test_update_user_password)

TODO:
Write tests for User model
 - unique usernames

Write tests for Views
 - return CORS headers on each response to API

users api routes
 - get user by username should use same get route as ID, it should check if integer or string
 - create user should return username successfully created
 - change /token route to /authenticate

Add foreign key to tie Trips to Users
Add tests
Write database migration scripts