Extract credential handling into its own module

Will be used in Docker V1 and APPR protocols

auth/test/test_credentials.py

@@ -0,0 +1,30 @@
+from auth.credentials import ACCESS_TOKEN_USERNAME, OAUTH_TOKEN_USERNAME, validate_credentials
+from auth.validateresult import AuthKind, ValidateResult
+from data import model
+
+from test.fixtures import *
+
+def test_valid_user(app):
+  result = validate_credentials('devtable', 'password')
+  assert result == ValidateResult(AuthKind.credentials, user=model.user.get_user('devtable'))
+
+def test_valid_robot(app):
+  robot, password = model.user.create_robot('somerobot', model.user.get_user('devtable'))
+  result = validate_credentials(robot.username, password)
+  assert result == ValidateResult(AuthKind.credentials, robot=robot)
+
+def test_valid_token(app):
+  access_token = model.token.create_delegate_token('devtable', 'simple', 'sometoken')
+  result = validate_credentials(ACCESS_TOKEN_USERNAME, access_token.code)
+  assert result == ValidateResult(AuthKind.credentials, token=access_token)
+
+def test_valid_oauth(app):
+  user = model.user.get_user('devtable')
+  oauth_token = list(model.oauth.list_access_tokens_for_user(user))[0]
+  result = validate_credentials(OAUTH_TOKEN_USERNAME, oauth_token.access_token)
+  assert result == ValidateResult(AuthKind.oauth, oauthtoken=oauth_token)
+
+def test_invalid_user(app):
+  result = validate_credentials('devtable', 'somepassword')
+  assert result == ValidateResult(AuthKind.credentials,
+                                  error_message='Invalid Username or Password')