Move config provider to _init to decouple from app

remove app references from validators

util/config/validators/validate_github.py

@@ -1,4 +1,3 @@
-from app import app
 from oauth.services.github import GithubOAuthService
 from util.config.validators import BaseValidator, ConfigValidationException
 
@@ -7,7 +6,7 @@ class BaseGitHubValidator(BaseValidator):
   config_key = None
 
   @classmethod
-  def validate(cls, config, user, user_password):
+  def validate(cls, config, user, user_password, app):
     """ Validates the OAuth credentials and API endpoint for a Github service. """
     github_config = config.get(cls.config_key)
     if not github_config: